The two comments of mine you quoted here were not in any way at odds with each other.
I didn’t miss that at all. Like I said, the two lines were entirely compatible and usable together. If you don’t want to call them different editions, fine; it’s a semantic difference. We are not disagreeing on the actual substantial details, just on what word to use to describe them. However you prefer to describe the relationship between Essentials and classic 4e, that’s what I think the relationship between 1D&D and classic 5e will be.
I think you have some baggage with the word “edition” that
@Marandahir and I do not. We are in agreement about what the relationship between 4e and Essentials was like. We just have different words we prefer to use to describe that relationship.
I agree substantively with everything Charlaquin the Goblin-Queen said above.
For what it’s worth, I do think WotC has baggage with the term edition too, and that’s why they didn’t call Essentials 4.5e. This is the exact thing they did in 2010, only giving us a D&D Next style playtest to make sure we want all of it, first.
It’s a continuation of the current game, republished with all the errata they would add today, with substantive changes where need be, allowing for usage of old materials with the new to some extent, though the balance may be off because of changing assumptions. There were updates to the 4e 2008 PHB classes given but they were locked behind D&D Insider Class Compendium articles that updated their formatting to the Essentials wordings, and they didn’t reprint the 2010+ 4e PHB with the errata once Heroes of the Fallen Lands and Heroes of the Forgotten Kingdoms were the new thing to buy.
Monsters were rebalanced, Themes were considered an option for everyone instead of something only Athasian characters got, higher level passive class features were a now thing. Cleric (Templar) and Wizard (Arcanist) did indeed show how they could exist side by side with Warpriest and Mage respectively (and Witch and Sha’ir, for Wizards), but there was no attempt to show how Seeker fit with the base Ranger, the Scout, or the Hunter. IS it another Ranger subclass or completely it’s own thing? Narratively it’s essentially a fully magical Ranger, the opposite end of the spectrum from the 2008 Ranger, with Scout and Hunter occupying middle positions.
Some builds and subclasses were narratively stepping on each other’s shoes, because Essentials was designed to share narrative space only with other Essentials, not with the 2008 PHB. Mechanically you could Def pick and choose and I often did. But this was the big thing 4e promised not to do: present splat books that didn’t recognise each other, since everything was now core. 3.5e had a dozen iterations on the same concepts, but with different mechanics. 4e promised consolidation and simple elegance. Essentials muddied the water - for good reasons - but to do so meant to mostly ignore anything that wasn’t Essentials. The idea was that you’d have a lot of DMs saying, Essentials Rules Only, much akin to how AL used to say PHB+1.
The only real difference with One D&D and Essentials is the Playtest to make sure enough of us want to use what the designers want to make, or if they need to change things up. 4e and Essentials were excellent refinements of the concepts from Tome of Battle, and I’d happily play in that Sandbox again if I had a group deadset on it. But it wasn’t what the player base of the time wanted, and each iteration broke the player base further.
They don’t want a plurality of us going off to play Level Up instead of One D&D because we decided it was a better refinement of 5e. And they don’t want a plurality to stop buying books because we’re happy with the 2014 game and have enough DM’s Guild products compatible with it to last a lifetime. They want to create new books that will not only carry over a majority of their players but will also grow their player base. And that means they learned the lesson of not acting like they’re changing the edition, and making sure any changes they do make are things a majority of the player base and target demographics want.