It would not be premature wear because there are no moving parts to an air bag. It is like a basketball you fill it up with air and you can deflate them if you choose to. I let all the air out of mine when we are at an RV park. Then I put the slides out, but, NO that would not be the problem for the air bag to fail. Maybe something was rubbing on it and it wore a hole through it, or something else, but not worn out because your slides were out.
Well it is good you still had warranty on it. That is why when I bought my coach I also bought an extended warranty, since I planned to keep the coach for a long time. I got a seven year extention on mine. It will be up this year though.
2002 Gulf Stream Scenic Cruiser
2018 Buick Envision Essence
Neway Freightliner chassis
Aventa II Blue Ox