I may be incorrect, but delamination is the separation of the fiberglass from the backing board, which generally occurs on side walls, and which is totally different from a separation of the cab from house section. A tell tale sign of delamination is the bubbling effect.
Yes, delamination can be caused by other things than water leaks. I remember reading here about one guy who was part of, I think, a recall, that had a delamination problem caused by the dark decals getting hot in the sun, and the head caused delamination of the fiberglass glue underneath.
But it's frequently caused by water leaks. Mine are. I have delam under my kitchen window caused no doubt by a leak there.
I'm not going to go trying to rip things out to fix it. The RV stays in covered storage now and is only out in the elements when it is being used. A little water now and again won't harm it any more than it is in the grand scheme of things. It's 24 years old.