The delamination itself is not a problem in most cases but if it is a result of water leak you have a serious problem that needs attention. You've got to find and stop the leak, which may be some distance away from the delam site. Then you may have structural damage to deal with as well.
Some early-mid 90's vintage rigs had sidewall delamination problems due to poor glue-up procedures at the factory - I had a 96 Southwind that suffered from it and I never bothered to fix the spots, which were not real noticeable. But that kind of delamination is the exception rather than the typical, so inspect carefully.
It's hard to tell the cause of delamination for sure, though. You need to feel around for signs of soft wood underneath the delam and at the floor and ceiling joints below and above. This may require somewhat of an educated eye and hand and perhaps the removal of some carpet, interior wall panel, etc. for a closer inspection. Any softness, crumbling plywood or particle boards, stains, etc. are signs of water leaks and the likelihood of structural damage under the skin.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL