I'll be honest here, and please don't take it the wrong way, your insurance should cover it. That is why you have insurance on it. It was an act of God. Disney could not control how that tree would react to a certain wind, etc. We should all just take it in stride and continue enjoying our vacation. Clearly, if it was a short in the electrical box that Disney installed, and burned up your camper, that is a clear issue for Disney to take care of. A branch falling is just an accident.
Its when we demand campgrounds to pay for every little thing that we start complaining about how bad the campgrounds look with no trees. Disney would just strip out all of the trees if they were asked to pay for every act of God.
I am fairly certain that we love FW because of all the trees. I believe the atmosphere they have created makes for a wonderful camping experience. I, for one, would not enjoy it if there were no trees.
So, my point being, claim with your insurance, and go enjoy that mouse.... I assure you, its more fun. Disney "should" do something nice for you just to take the edge off. I am not saying they have to, but Disney's history of kindness makes me believe they should do something nice, even if its a little thing. If it can bring a smile, it will be worth it. Your camper will get fixed by your insurance.
Just my opinion.