So remember when we first saw concept art of Ulysses and it had all those different dusters with flags on them. I was watching the trailer and there were quite a few shots of to people fighting (u and Ulysses) both wearing an overcoat my theory is that the over coats in the concept art may not be Ulysses' but meant for you depending on which faction you sided with because why would Ulysses the USA's #1 fan have a legion duster....just a thought.

He was a frumentarii, right? he might've had a legion one duster from back then.

Might have had some reason to have one with an NCR flag on it as well; probably for infiltration purposes as a one of the frumentarii.

During the trailer I swear that is the Courier who is always seen wearing the coat, Ulysses only near the nuke.

We will be getting costume like Ulysses before we get to him, that trailer shows that.