Well, it's no secret that TPO is very good stuff for RV roofs. So was the one piece (no seams) aluminum sheet painted white and wrapped around a short distance down the side wall. Both will last longer than most RV's or longer than one will own the RV. Both are easily patched. Both, while being a best possible choice, are very expensive and best to have as OEM on an RV as you can basically forget about ever replacing them short of an accident, a tree or large branch falling on it, or a tornado/hurricane which would mean you first finding the RV or what's left of it to attempt any repair!
Then we get to replacing the roof material on a 10-15+ year old RV that may have a rubber membrane or other second best material as OEM or even a layered on aftermarket coating. Without insurance paying the bill, a big decision looms as whether to spend perhaps twice as much + to put the best on an old RV as how long will the old RV be viable for use or how long before you sell it and will you ever get any or much of your extra money spent back when selling it or junking it?
Most insurance adjusters would TOTAL a 10-15+ year old RV with a replacement required roof etc except for with the very high end RV units. More so if it had to pay to re-roof a mid level or low end RV with anything like TPO or one piece aluminum sheet. Even if replacing a rubber membrane with another rubber membrane with it's high labor cost and other supplies needed like re-decking etc would be very iffy to have done at a repair facility due to the costs. Insurance companies aren't stupid and have formula's they work with and what they will need to spend to replace the RV with a close year RV same type of model they can find on the wholesale etc market, which rules or just total it and cut a check for their calculated value minus the deductible. There are some maverick cases but they are few and far between.
To begin with, rubber membranes only have a warranteed life when new of 12 years and a 10 year old OEM roof means it's life cycle is 80+% exhausted. 15 years old is over 100% of expected life cycle already gone. An insurance company sure has a argument and they have all the marbles and you are hoping to get some of them. I wouldn't bet on high success unless the existing roof looks to be in excellent condition upon adjustment inspection as if it's been covered much of it's life or kept inside out and out of the sun.