Well, in the interests of full disclosure I should say at the start that I have no problem with AoS, and indeed rather like the revisions and streamlining of the rules system in particular, and the fluff change is really just a shift from a semi-historical fantasy setting to one more directly inspired by (principally European) mythology, and Nordic mythology especially.

With all that said, I think it is one heck of a stretch to claim that the creation of AoS was some elaborate conspiracy on the part of Games Workshop to assassinate all things Elvish in their games settings. While they haven’t gotten around to developing any of the Aelf factions in AoS yest, those factions have a significant presence in the fluff and have popped up in the Silver Tower game as heroes – it seems clear that GW will get around to exploring them in time, even if their new iteration is not an exact match for the old High/Dark/Wood elf subdivisions.

Also, if we are going to claim that lack of development of a race from a Grand Alliance book indicates a conspiracy to get rid of that race, then what of the Steamhead Duradin, who have no models created after the birth of AoS? What of all the Undead factions bar the Flesh Eater Courts? What of the Free Peoples (non-Stormcast humans)? I have a particular soft spot for the Vampire Counts of yore (now Soulblight) myself, and yet I am not going to assume that GW is planning to Squat them just because they haven’t had their own Battletome or any new models yet.

The hard truth is that the Warhamnmer setting that was was hemorrhaging money for GW at an unsustainable rate. They simply couldn’t justify continuing to absorb that loss indefinitely, especially when at its worst the modelling supplies sales made up a greater part of their income than sales from the Warhammer model ranges themselves. GW is still a company that is answerable to its shareholders, not a charity for war gamers – something had to give. All reports indicate that the situation was so bad that, in the end, GW was faced with a stark choice; effect radical change to the Warhammer setting as a concept (along with its rules set) such as that performed with AoS, or just Squat the entire game universe and give it all up for a bad job, which would not only have done massive damage to GW as a war gaming brand, but would have been a serious blow to confidence in the entire war games industry. It seems clear to me that they made the right call, especially since, in the year and a bit since the launch of AoS, the Warhammer war gaming community has actually rallied substantially and, while exact numbers of gamers aren’t known, AoS now accounts for a much healthier share of GW’s income, apparently somewhere in the region of 30 to 35% of its takings, as opposed to the serious net loss the old Warhammer game represented to the company.

This was never about anything so weird and petty as some vendetta against a particular type of fantasy race trope – it was motivated by market forces and cold, hard cash, which is not surprising given that GW is, after all, a company in the business of making money. Crudely expressed, if the Old World setting had kept bringing in the green, nothing would have changed, but it didn’t, and AoS was the measure GW took to revitalize the setting. 30 years of lore doesn’t help you much when no one is buying anything you produce, but happily all that lore still exists, much as everything that happened in the Heresy Era still exists for the 40K setting, even though it occurred 10,000 years in the past in the fictional continuity. It just isn’t the focus of the current game timeline.

As for 40K Eldar, they have existed in one form or another since the earliest days of 40K, and are one of the principle species of the setting woven throughout the core narrative. GW probably couldn’t get rid of them even if they wanted to, since if they did it would mess with how all the other factions in the game relate to one another.

Also, as @fleetey observes, it is not as though the Eldar have had a dearth of new release over the last few years, with the Eldar now spread over three factions – Craftworld, Dark and Harlequin – with the Exodites and Corsairs still regularly mentioned in the fluff and a new rising multi-faction sect of Eldar having just been announced in the Ynarri, who have been specifically written to offer the Eldar an out from their prophesied extinction and a route toward the renewal and regeneration of their civilization – why would GW bother doing that if they want to get rid of the Eldar? Why not just write a campaign depicting the Rhana Dandra and be done with it?

Where do you even get this notion that GW wants to get rid of all Elven and Elven type races form their universes anyway? I can see no shred of evidence to support the claim. You could just as well say that Blizzard is planning to axe the Protoss, or Disney wants to destroy the Star Wars setting, with as much evidential basis.