If D&D needs a bird race in the core, then I see no reason not to use Aarakocra. They existed through 3 editions of the game, and had rules to use them as PCs. That's good enough for me. Probably the claustrophobia should be toned down a bit though.
I'm not familiar with dire corbies. Then again, according to this article, they're old Fiend Folio monsters that didn't get updated until 4e, so that doesn't sounds like they're one of the better entries from the FF. And my impression of FF is that it was the source for the biggest number of lame 1e monsters (let's face it, every edition of the game has had some really silly stuff). For every interesting classic monster like the gith races, FF had something like the flumph.
Wyatt doesn't even seem like he wants to do anything with the gyerian, so why'd he bother mentioning it? I can see how it might seem silly, since it was a Basic monster, and Basic at this point was pretty much being aimed at younger players. Still, while I'd like to say that it might have potential as a low-level encounter, I was never all that impressed by its entry in the Mystara MC either, and I've never really felt a need to use it.
Kenku and tengu probably should be the same monster. But then, kenku seem like they were popular in the past. I dunno. Still, I have no problem with them being in core.
Interesting that other have mentioned how the nagpa resemble skeksis, because that's what I thought of when I first saw them in the Mystara MC. Though IIRC they were given a CN alignment in 2e. Never used them, but they have potential.
The raptorians don't sound interesting at all. And really, they feel redundant when compared to aarakocra.