They never forced it no. Unless you used Eberron or the Realms, in which case you were asked to accept a major retcon.
I'll give you that! While I think that the eladrin race was a genius addition to D&D during 4E, the way the race was retconned into the Realms was . . . awkward. I liked the eladrin citadel in the Moonshaes rising out of the lake into the material world, but the switch back-and-forth with Sun and Moon elves was jarring and not handled well. It was also confusing that some elven races were *always* eladrin, and others just entered the world for the first time. If the Realms had been completely reimagined (a la Battlestar Galactica), I would have probably been fine with the retcon of Sun elves being eladrin (or was it Moon, or both?).
Edit: The entire 4E "Spellplague" Realms goes along with the core 4E cosmology changes, IMO. Lots of really cool and interesting ideas, but with awkward and difficult retcons that did not respect the developed canon and continuity of the game or the setting.
I didn't mind their inclusion in Eberron, because they were an addition, not a retcon (if I remember correctly). The trapped feyspires throughout the land were an interesting addition to the world, IMO.
I'm not sure the elf subrace thing really needed to simplified. Warcraft managed to have elven subraces just fine, and no one got confused by how Legolas was different from Galadriel.
We're not talking Warcraft or LotR, we're talking D&D. And elven subraces in D&D have long been an "issue", albeit one that some folks felt strongly about and others didn't even notice. Multiple subraces that aren't all that different (high vs grey, wild vs wood) in the core and an overabundance of offshoot subraces. This "problem" (not really a problem, just a thing) did not *need* fixing, but I welcomed the cleaner break down of eladrin-drow-elf in 4E, and I was not alone at all on that one. On the other hand, many not-all-that-different subraces of elves is a part of D&D history just like the wild Great Wheel cosmology and calling a class "fighter" when a much better name would be "warrior". Change it at your own risk, which, of course, was part of why 4E was so divisive among fans.
I like eladrin and the addition of a high fey race to D&D but the reason they did so was rather insulting to our intelligence.
No, no it wasn't. Not in the slightest. Absolutely no one's intelligence was insulted by the elven subrace change in 4E. Love or hate the race and the various reasons behind the change, but the change itself was in no way insulting. Jeesh.
I do think WotC erred by not realizing how passionately many long time fans would hold on to the many sacred cows of earlier editions when designing 4E, and would have been better served by, well, by something like the 5th Edition! But while it can be argued that mistakes were made, no insults were intended or given by anyone at WotC during the edition change-over.