I knew I recognized this guy from somewhere ...

[Enkidoh]

The entire 1.0 trailer can be determined to be in the First Shard at this point.

the Midlander and the other characters we see are Arbert and his friends.

Guess the entire time it was just Arbert seeing a vision about what was happening in our world while he was going through his own issues in his world being the First.

Wrong, wrong and wrong again, because in the 1.0 opening Derplander goes off on an Echo trip to Mor Dhona and sees the Battle of Silvertear Skies (including the destruction of the Agrius and Midgardsormr's death), and... well.. the Garlean Empire (and Middy) does not exist in the First. So the battle never happened there.

And another nail in the coffin of that arguement? The 'Resolve' leveplate that Derplander picked up off that counter... has Limsa Lominsa stenciled on it. And Limsa does not exist in the First (it's called Eulmore instead.). Yes you could say that's a retcon but the fact remains: 1.0's opening movie is the Source. The adventurer's guild shown in the 1.0 opening movie Square Enix Visual Works used a very early design for the Drowning Wench to design, only for Tanaka to change plans at the eleventh hour, thus making the opening movie not match up with how things actually ended up in game (like how the Heavensward opening movie had Hraesvelgar leading the Horde attacking Ishgard instead of Nidhogg who it should have been). But it's still on the Source either way.

The First having these throwbacks is simply for fanservice reasons and doesn't necessarily mean anything deeper (like MrThinker I agree that roe isn't the same person but just looks like him - he's not even manning a leve counter for Azeyma's sake!).