Obviously MC is not running from the UNSC.
Obviously he’s taking Cortana’s chip to some random place to obviously get fixed.
Obviously he’s wearing a cloak to protect his clearly damaged from whatever storms may be thrown at him, obviously.

Obviously we know very little about this game and are speculating.

This is not an in-game trailer and people shouldn’t take it as one. This doesnt happen in the game at least the way we saw it.