Nah, the problem with High Elves was subraces not existing -- now that they do (regardless of whatever Blizzard calls the system), the only thing to wait for is another WoD->MoP->Legion scenario where Blizzard has to bait people back with x big thing (Demon Hunters/Illidan/Legion threat in the case of the Legion expansion).
We're thankfully much closer to that with how terrible BFA has been for Blizzard's public image, but you have to account for how many people will feel Blizzard ""redeemed"" themselves with flying (already announced for 8.2), Vulpera, Junker Gnomes, any other Allied Races Blizzard might try to shoehorn in (if that's even possible at this point, but we are "missing" 2 allied race models if that's how the system works, for Worgen and Undead), and the inevitable player sub cycle of the next expansion being announced -- 8.3->9.0 period will bring a (relative) ton of players back even if it's garbage simply because it's something of a habit for whatever reason (marketing/nostalgia?) for players to sub at the end of the expansion in "preparation" for the next.
At this point, High Elves are all but inevitable, especially with how the discussion has somehow lived a decade+the Ioning+the community bludgeoning that happened as a result for months afterwards. It's just a matter of if it's coming in a year or in ten, because they're not gonna break the glass until they feel like they have to. As Bellular has pointed out though, there's a deep sense of lost faith in Blizzard from the community right now, so I (personally, as someone who is pro High Elf, so there's a disclaimer) think High Elves are coming sooner rather than later. I have no idea how they handled their whole situation so poorly thus far.
I don't know if High Elves would be enough to make me resub after they butchered the GCD, but it'd be enough to talk the boycott over again with friends and family for sure.
And for sure, they'll use a tweaked Blood Elf model, like the Night Elves and the Nightborne. It'll just be different posture and idles but that's what most people would be happy with anyway, I think. Void Elf explicitly didn't do any of that.