Ofc I admit it, as we both know, the lore is then written and designed to make the case for playability. So it is no surprise that the lore on high elves is thin, but my suspicion is becaue blizzard really doesn't pay attention to factions or groups that ren't the main focus.
What is notable is that they kept the high elves, and continued using them. I think this back door was intentionally left open as the classic tolekkiin high elf fantasy is not an option they wanted completely removd, just not prominent to give place to the more u nique and original blood elven identity. Still thatwasn't the only motivation.
High elven faction is and always will be part of the high elven or blood elven racial lore, high elves showing up in places like WotLk and beyond may have irritated short sighted people who failed to see that their inclusion was par tof the blood elf (also called high elf)
race lore. Pretty just like highborne, nightborne, Illidari, Farondis, Moonguard are all part of the night elven racial lore though the Darnassian faction is predominantly druidic and Elunite based. But like high elf, night elf is both a race and a faction, and people often refer to the
faction as much as others refer to the
race. So certain statements that are true for the race aren't true for the faction and vice versa.
As we are not developers, we dont' determine who is playable nor why, lore as a reason is pointless because as @Ielenia feels and despite your not incorrect conclusions from her, lore can be changed to suit whatever purpose the developers have. I think a lot of people find you insistence that the developers will never do high elvs quite annoying as you aren't one, yet you go to a long extents to tell them why and how they can never be when dno matter how good your reasons, they fully w ell know is not definitive nor up to you. But I wonder if you pick that up from some of them, while others I feel aren't that irritated by you and enjoy the back and forth, hence their dedication to keep this up.
I was speaking in more absolute terms, the lore still determines things, and does drive a lot of content, however gameplay is responsible for a lot of cjamges/ Sp,eto,es ot os easy to tell, but most of us usually guess which is which based on thetype of change and the extent of it. Blood elf horde addition if you were arrround in classic, you would remember was the solution the deves felt would address the horde player number deficiencies, therefore there addition as a playable race on the horde was not lore motivated, but the lore adjusted to make it so. Other interviews around the time had High elves and Goblins originally intended to be the next playable races with Northrend the first expansion, although Outland was never taken off the tables. The decision to go with outland Chris directly said was because it offered something newer and a bigger punchline with what they could do with the lands and features - I believe he mentioned the part sci-fi assets in it too for the Draenei as part of the factors in its afaovur, as they really wanted their first expansion to be a big hit, knowing that a misstep on it could really hurt their huge and growing popularity.
Whether blood elves as a race influenced outland being picked or vice versa, it sovle a lot of gameplay issues, and thus we came to know as we had suspected and was later confirmed concerning Tauren druids, alliance warlocks, night elf female druids and NElf male priests that gameplay was winning over lore decisions for some important things.