if they publish a new version of an old setting without noting that's it new and different, or what the traditional setting allowed, they are deceiving anyone who has ever heard of Dragonlance prior to the new product. Not to a great degree, but it is happening.
This is simply not true.
Marvel/Disney is not deceiving movie-goers about Aunt May. About whether or not the Scarlet Witch is a mutant. By having filmed multiple versions of the Death of Phoenix neither of which involves Phoenix on trial for genocide on the moon at the hands of Xavier's alien empress lover.
No one was deceived by LotR films which replaced Glorfindel with Arwen, and freely played with the sequence and geography of events in and around Rohan and Gondor.
People who care about these differences can learn about them from the multitude of commentaries on them that inevitably will spring up.
The official setting absolutely is an objective thing. Your table then makes subjective changes to it as it sees fit.
This is another claim that is not true.
The WotC Greyhawk setting book has completely different population figures from the TSR-era ones, revised because Eric Mona and others thought the early figures too sparse. The same book changes how druids and bards are described, to try and achieve some sort of fit between the rather baroque AD&D rules and the 3E ones. (Even TSR books did something similar - Turin Deathstalker the Guildmaster of Assassins gets redescribed as a fighter rather than an assassin, when that latter class is abolished.)
3E-era Forgotten Realms used a different set-up for its Outer Planes than Appendix IV of the AD&D PHB.
More generally, these are commercially published fictions written for the amusement of the fan-base who purchases them. They're not encyclopaedias. They're not the artistic visions of a single creator (and even a world that is, like JRRT's Middle Earth, is not an objective thing - as is well known he had many version of various stories about all of his Ages, including revisions between editions of published versions of his books).
Even in its earliest published form, there were various published ideas of Krynn: in the novels, for instance, casting spells caused tiredness to wizards; but there was no analogue to that in the game rules for magic-users ostensibly describing the same imaginary world.
You are basically saying 'there should not be a setting'... willing to burn down the house so some people can be kept in the dark about whether orcs should be on Krynn, so they never even have to decide to add them
"Burning down the house" has no aptness here as a metaphor.
WotC is going to publish a book, about an imaginary place. It is free to present that place as it likes, and will do so. If you want to imagine the place without Orcs, you're free to do so. Others might differ in what they imagine. Maybe you'll even have to ignore a few words of what WotC publishes to do your imagining. Why does it matter? Who is being harmed? What damage is being done?
Your memories of other books you've read, in which there are no Orcs in Krynn, will not be damaged. Nothing will stop you continuing to imagine the world as you do. Why does it matter that some other people might think of something different when they think of Krynn?
Ignoring the original lore has happened countless times in various big block buster franchises and we all know how the majority of those turned out. It is also likely the reason why we're losing Henry Cavill as the Witcher.
A former Witcher producer Beau DeMayo wrote: “I’ve been on show – namely Witcher – where some of the writers were not or actively disliked the books and games (even actively mocking the source material.) It’s a recipe for disaster and bad morale. Fandom as a litmus test checks egos, and makes all the long nights worth it. You have to respect the work before you’re allowed to add to its legacy.”
I don't know which blockbusters you've got in mind. Some of the blockbusters I can think of that ignored "original lore" include the LotR movies, the X-Men movies, the MCU movies, the recent Star Wars movies, David Lynch's film of Dune, the original Conan film, and Lawrence of Arabia.
That's before we even get to the point of how the presence or absence of Orcs in Krynn is remotely connected to "respecting the work" or "actively disliking it". And to what counts as a change - as per my post upthread, when D&D was first published Orcs and Goblins were the same sort of beings (just as is the case in JRRT's works) and the differentiation of one from the other at the time DL was first published was different from that which obtains now. Given that WotC is intending to publish a setting book that supports the game it currently publishes, that includes fiction about Orcs and Goblins that is not the same as what existed in the 1977 Monster Manual, if it includes Goblins in Krynn it is also presenting something different from what was originally published.
You've not read the entire thread, but came in late into the conversation.
I came into this thread after posting in two others about DL.
One was a thread in which there was outrage about whether or not Knights of Solamnia can be women, and/or can be clean-shaven.
Another was arguing about whether gods who inflict collective punishment for the sin of pride (in the form of the Cataclysm) can nevertheless be good gods.
In my view both threads have many posters who seem to be completely uninterested in what is actually interesting about DL as a work of fiction - a study of loyalty, honour, family, love, betrayal, faith and similar themes and values, that uses dragons and knights and knights riding dragons as some of its key tropes. I don't think those who are obsessing over Orcs and moustaches are showing any real respect for the work at all. To me, they seem to have missed its point.