It's interesting that, in the Field Trip book, Superman is wearing his MOS suit, then all the covers, etc, have the new BvS one.
Obviously, the closer to MOS events are in these prequel comics, the more sense it makes for him to have the MOS suit, but if BvS starts with Kal in his new suit (putting side the parts that are overlapping with MOS), then they
could have the "change" happen at any point between the films.
So, it would seem that putting him in the MOS suit in the Field Trip book was a very deliberate decision.
Obviously I'm taking a bone and running with it here, but I always wishing for them to address these kinds of changes between films.
Nolan did it with TDK, though that was a bit different than most films that do these revisions between films, as it was done as a whole, in film, upgrade.
The Amazing Spider-Man 2 was one of the worst, although they throw a bone that way with their prequel comic as well, with his TAS suit getting battle damaged, and at the end he just says he'll need a new one.
That's something, although hardly satisfying within the movies, especially with how dramatic the costume change was. Hell, even the whole look of the film, everything was so drastically different, that it was all but unrecognizable as a sequel. Cast was the only notable connection.
Any who, the Superman suit change is pretty minimal, relatively speaking, and probably won't even be noticed by the majority of viewers, but the deliberate choice in the books is interesting, and got my mind running.
I'll shut up now.