I don’t think that specific shot really hints at that, though obviously almost everyone has some kind of theory about how time travel will or won’t be a factor.
Maybe when the gang first reunites, Cap grabs that uniform out of his locker in the Avengers compound since it’s the first time he’s been back there since Civil War, and the more recent Avengers uniform he’s been wearing since he left is obviously all beat to hell. But who knows?
Plus, there was no infinity stone in Winter Soldier, so there isn’t an obvious reason he’d need to wear that S.H.I.E.L.D. uniform again for time travel shenanigans.
I’ve lost track of exactly what we know and what’s speculation—I’ve heard the movie starts with a time jump to some time after the snap, but from trailers it looks like at least some scenes will be picking up almost immediately after. My best guess from today’s footage is that in the immediate aftermath of the snap, the very first thing they do is somehow get Tony and Nebula to Earth with the gang, and from there, plan A is they just go right back out and try to fight Thanos again. Maybe act one is them thinking that even though they’re missing so many people, it’s worth a shot to try another united, direct assault. Maybe that’s the confrontation with Thanos we see here. I could even imagine the movie starting with them actually beating/killing Thanos, before realizing the gauntlet is spent and taking him out accomplished nothing.
