I like the design on the character it's very Falco like.

Yeah it's neat. I wonder if that's intentional, wouldn't be the first time they would do that, there's been characters that look like other Nintendo characters before (especially Mario and Luigi).

I think in MM the were masks that looked like Star Fox Team members, it very well maybe intentional.

Sure were.

I think the bird people created hyrule and hylians (before skyward sword and before the backstory of skyward sword) now they are coming back to destroy them because they're advancing as a society. Then, Link finds zelda after all the destruction and they decide to do the 100 years sleeping thingy. So this trailer is before the e3 footage.

Going to just keep things in the official thread.

- At this point I think it's dead certain to be the TP timeline given the ruins of HC Town.

- You will at some point reclaim the Master Sword.

- The bird people are most likely the same race as those in WW's timeline who lived in the Death Mountain islands, like the Koroks they've some how appeared in TP's timeline for what ever reason. I say this because of their diverse use of their wings to fly and utilize them like hands, their morphology matches the race from WW as well.

- The bird adventurer seen in the trailer resembles Falco in design and has a scarf similar to HW's Link as well as an interesting looking Bow. He flies off two what looks like an airship or flying settlement shaped like a bird, this very well might be the the floating structure seen in the distance in previous footage.

- Two characters briefly shown both female or they may be the same character in different attire as the faces were never shown. One is very likely Zelda

- Game Award footage pretty much confirmed Hylia is much more acknowledged in BOTW's era as the statues seem to play a key role as it was a Hylia statue they were trying to get to.

- Lizard enemies in the LP footage had control over the electrical element as well as chameleon like ability to hide in the surroundings and also have electrical arrows, it's possible you may be able to obtain such arrows as well seeing as both Fire and Ice arrows are available to the player.

- Seems the will be NPCs travelling across Hyrule as well, trailer showed some NPCs fighting enemies but not clear if that's just for a cutscene or actually will be a part of real time events.

- Two settlements shown, first being a peculiar structure with part of it shaped like a horse's head, going by the brief glimpse in the trailer it could be a market or trading post for traders/adventurers/hunters. Second settlement shown is a village.

- In the trailer the artwork clips have some significance in highlighting the situation in BOTW, the Sheikah eye signals nature reclaiming the land from the kingdom, the second and third art clips highlight the people of Hyrule live their lives in one of two ways (in a village or out in the fields surviving) while the final art clip signals the calamity that has taken place.

Forgot to mention this now means essentially in all 3 timelines the is a point where Hyrule falls into ruin, WW it got conquered and had to be flooded, in LOZ Ganon has conquered Hyrule and now BOTW the Kingdom has been decimated.

So I think it's pretty much official that the blue is some kind of uniform. Perhaps some kind of orchestrated resistance to Calamity Ganon's servants? Maybe the remnants of the Sheikah and the Hylian Royal Family? Perhaps the Hylian Royal Family is completely hidden among the Sheikah or general populous. I'm holding out for a situation like the Dunedain in LOTR, where the Hylian Royal Family and maybe Hylian race (that is, the long-pointy-ears ones) are in hiding as sort of resistance fighters, only going by this bird race with the blue as well, it would seem this is some sort of coalition?

Yes. Nintendo mentioned that you will get in a very important point during the game.