Travel trailer have to be resealed every few years. This is considered maintenance. They would not have been able to assess this until it was torn down and able to determine what caused the damage. Some insurance companies will cover the resulting damage but not the cause. The roof is the cause so the replacement of the roof would not be covered. but the inside might be covered. Unfortunately the damage to the roof is wear and tear and fault maintenance as you did not maintain the trailer by having it resealed periodically

You should have just taken responsibly to fix a leak in 7 year old trailer instead of trying to get over on your ins.My guess is you mis led the ins. and are not telling us the full ….then they determined it was not anevent that caused leak and dont pay for manufacturers design flaws..sometimes when you try to be greedy, It doesn't always work out in your favor.