Come on guys! It's finals week, 3v1 now?
You seem to overlook the Fokka of Zelda II. They are also humanoid bird-like creatures in Zelda. Though they act as enemies and do not speak in the game, I would still argue that they are indeed intelligent judging by the way the fight.
Alright, here is why it can't be the Fokka. The Fokka are monsters which all come from Demise. :/ Why would a monster ever help you without being threatened or by bribing you to leave them alone? (Link's awakening was all a dream, so that Goriya never actually gave you a boomerang because he didn't exist) Can't we all just assume at this point that whatever these bird people are, they are probably from one of the "free peoples" so to speak, of Hylia? Just look at Kass! Is he a monster? The guy has sheet music and he points you in the right direction. They are most likely a species created by Hylia at the least. :/ But maybe people will make peace with some of the bad guys. That just seems unlikely.
The change from Zora to Rito wasn't some gradual, natural evolution; the Goddesses changed them all at once to prevent them from being able to swim to the remains of Hyrule, meaning the evolution they became is what the Goddesses definitely intended their final forms to be.
Where the heck did you get this from? I just looked for this in the historia and it said nothing of the sort.
How do feathers equate to baggy pants?
You have heard of a pillow haven't you? As for clothing style changing, why would it stay the same? The clothing style of the Hylians changes all of the time.
And for Moblins being smart. Yeah, who said monsters HAVE TO be dumb? Moblins are smart in every game besides OoT. They run over to places when you make noise, they can write letters, they can talk, they know MMA, they walk around bombs, they use sheilds to block your attacks. Monsters can be smart, whose to say that moblins started out brainless? They just didn't have the programming efficient to make intelligent AI back in the old days.
And about Loftwings being important. I had said important to the "story" what you mentioned had nothing to do with the story.
Well, It's finals week for me so I should get busy with my homework. The only logical conclusion that I can see is the bird people being a further evolved Rito. I see absolutely no reason for the Loftwings to return, heck, maybe it's a cross between the Rito and a Loftwing? and if the Fokka somehow aren't actually monsters, it might be cool to see them return. :/ Those seem a little out there, and I can see actual evidence showing them to be the Rito (Koroks and salt). I actually hope we get to fight some of these birdmen, we fought the Zora in Alttp. But I suppose we'll just have to wait to know for sure...