I feel like I’m regurgitating a bunch of my favorite ideas from the ROTJ collaborative thread, but I’ve always liked the BTL-B Y-wing design and think it complements the OT’s Y-wing nicely.
That are the same ships.
The OT Y-Wings just have their armor panels removed because they are easier and faster to maintain this way.
Also the armor was total useless against modern fighters so it was already obsolete and just made the Y-Wings slower.
So it makes no sense to put them in ROTJ.