So we've seen winged Ixali in Allagan tanks, likely on the Floating Continent. This is kind of a big deal because there's an obvious setup for that in the Ixal beast tribe quests (TL;DR version from memory: according to some Ixal myths they once had wings and were able to fly, and the Ehcatl renegades want to find Ayatlan, a floating island that is their "promised land"/paradise).
Something is up with the Ixal race, Dragons, and Garuda herself and this is definitely going to play a part in Heavensward:
- it is said that Garuda fought and won (killed, and fed upon his carcass, turning her mad) against the Lord of Snakes in the distant past.
- The Ehcatl faction doesn't worship Garuda as their goddess, in fact they hate her.
- it's likely that the Ixali were once winged and able to roam the sky.
- one of the seven celestial dragons we've seen an artwork of suspiciously looks like an Ixal, horns and beak included.
- at one point the allagans got involved.
It should be noted that all Ixal names are made up from Nahuatl, a mesoamerican language.
In Nahuatl, Ehcatl is another name for a deity tradionally associated with Wind that was featured in FF8 (replacing Ramuh, eh) and whose name literally means "Feathered Serpent" (remember the aforementioned Lord of Snakes?): Quetzalcoatl.
I think the Ixali are the descendants of Quetzalcoatl, who's one of the Seven Celestial Dragons featured on the concept art, and one of the sons of Midgardsormr. At some point, the Ixali lost their wings (likely because of Allagan meddling) and most of them started to worship Garuda for some reason (Ascian meddling wouldn't seem too crazy).