The repurposing of archons as elemental warriors rather than celstial servants is clearly not, and not intended to be, an evolution of the prior canon. It is taking a cool name and attaching it to a new monster that the designers - rightly or wrongly - think is more worthy of the name.
But as for the notion of "change" vs "building", I think it is very much in the eye of the beholder. I am pretty familiar with a wide range of D&D lore - especially but not ony 1st ed AD&D - and didn't find 4e's changes "drastic". For me, they were about integration and enhancement, changing plot details to bring out thematic elements more strongly. (Which is also how WotC presented them in Worlds & Monsters.)
Sure, that might've been the intent. But I think it's important to note that what WotC thought were relevant "thematic elements" and what the PLAYERS thought were relevant thematic elements were often wildly divergent. A pretty meaty example of that is the 4e tiefling -- it grabs the "born of fiends" theme, but leaves on the table the "orphans of the planes" theme and the "unlucky birth" theme and the "many different kinds" themes in exchange for one true and unique origin for all tieflings that is common knowledge in the world and making them a race that breeds true.
The 4e tiefling is a drastic change from existing lore if those OTHER things were at all important thematic elements of the tiefling for you.
The idea that this is "disprecting" tradition is puzzling to me. It suggests a fixation on petty details of canon at the expense of thematic coherence.
An attempt to describe what people valued about a lot of monsters' stories as a "fixation on petty details of canon" is not only wildly inaccurate, it's kind of insulting. And it's the same kind of disrespect that the designers manifest in presenting One True Way.
D&D has always been a game that needs a group to tell a story. Where the book's lore intersects with what a group might find interesting in the moment is not consistent or predictable. Millions of vastly different stories spin out of blurbs of lore, and they use different elements of that lore in different ways. Bits of lore become the building blocks for different and divergent kinds of adventures, and thus become
really important to those adventures, and to the experience of playing through them. Tieflings being orphans who don't know their true origins might just be a poetic flourish you ignore, or it might serve as the basis for an entire character's motivation as they seek to understand the forces that produced them, and why they are outcasts in a diverse multiverse.
In fact, at the core of this "disrespect" is the hubris a designer must manifest when they deign to tell people what is "really" important about a given creature, what is "worthy" of being the Official Theme, what is "petty" and what is somehow higher in authority, by deciding that whatever pet theme they enjoy the most is the "true core" of the fictional game element and that thus of course no one will really miss those other unimportant bits of lore. The truth is that the diverse players of this game have used almost any random element as an important building block in their stories.
5e is being more careful about that (though they aren't getting it perfect...because TIEFLING!

). The 5e salamander doesn't pretend that your 2e salamander experience was somehow flawed or invalid by presenting a new story based on what some designer thought was "really" important. It presents more information, additional context, it builds on the lore without contradicting it. That additional context may or may not be welcome or interesting, but at least it honors the experiences of those who really loved some little detail about the salamander as it was used in the past.
Integrating dwarves, giants, Moradin and the elemental planes into a story of slavery and liberation with the possibility of future fall or redemption doesn't strike me as disrepectful at all. It is respectful - displaying sensitive attention to the best in what has come before, and re-presenting it in a way that brings out that best.
See, "the best" is a judgement call, a bit of subjectivity that reasonable people can disagree with. And it's inherently judgmental and more than a little egotistical to MAKE that judgement call: "Oh. I get to say what is The Best, and whatever I DON'T say is The Best is not worth the time to worry about, because it is not what I say is The Best. Whatever these millions of other fans think is The Best is either in accord with my designation, or they're not worth listening to."
This isn't a beauty contest. Mearls has said that the job of a designer of D&D is to support the players of D&D, and that support means letting
the groups make that judgment call. No dork in Renton can tell millions of people what they all should find interesting or worthwhile, especially with regards to things that they have already been using for 40+ years.
Arranging all those elements into that One True Story is saying that every group that follows some other story is doing it wrong, is doing it "not the best," is somehow not getting what is "really" important. But that's bass-ackwards: groups determine for themselves what is really important, because the best group experiences are customized
to that group and not decided from on high. WotC's job is to support what
we say is important, to empower DMs to make that call themselves, not to tell us what should be important.
You may as well say that the X-Men movies are disrepectful to the comic canon because they focus on theme and broad-brush elements rather than every bit of accreted detail of mutiple decades of serial publication.
The
IMMENSELY IMPORTANT bit you're missing here is that all X-men stories are passively consumed as told by other people. They can be good or bad, but they are not our stories to tell.
D&D is
our story to tell. It isn't Mearls's, or Wyatt's, or Crawford's. Or Gygax's or Cook's or Mentzer's, for that matter. People determined long before this One True Story was written down what they liked and didn't like about a given rules element, and it is disrespectful to those stories that have come before to imagine that you have the authority to determine for others what their stories should be.
5e's more cautious approach doesn't suffer from that disrespect as much as 4e's did, for sure. The 5e cosmology, like the stories of 5e monsters, seems to make a concentrated effort not to invalidate what came before, but to try and build on it. Of course, there's places where they ignore this -- for some reason everyone uses the Weave now which is just
*facepalm*.
And for clarity: If someone doesn't like 4e, that's his/her prerogative - I'm not arguing with that. I'm arguing with this notion of "change" vs "building", of "disprespect". I am strongly of the view that 4e built on past D&D in a deeply respectful way.
That might just be because you agree with the designers when they chose thematic elements to make central. My point is that it is not up to the designers to choose those thematic elements for us, it is up to each group to use the elements that they find the most thematically resonant for their own group in the moment, and the designers merely need to help us do that.
A story of slavery and liberation with elementals and dwarves might not be a story I'm really all that interested in telling. I mean, for me personally, introducing the themes of slavery into my games in ANY respect just sucks the fun out of the experience because for me, slavery was first and foremost that trans-Atlantic horror show of the Colonial-to-Civil War period in America whose echoes are still felt very personally by people I consider friends and mentors and I am not going to try and address that level of serious pain and suffering in a game about magical elves that I play as a bit of escapism and fun.
I'm not everyone, of course, and I wouldn't necessarily say it's anything more than objectively worse
for me, but the delightful thing D&D can do is adapt to my own personal desires and quirks and insisting that One True Story about slave-dwarves is the best D&D story that people can tell and the only story that's going to get any support doesn't help me play more and better D&D, it just makes me never want to use elementals and dwarves and giants and that whole sordid plotline.