For an 18 there sure seems to be a lot going on under there. I've never had a broken hangar on an RV but I have on a Jeep and it sure didn't look that deformed. I understand the dynamics at play are a lot different between the 2 but still makes one wonder.
I agree that the rusted break looks like it's been going on for a long time. I don't know quick rust works in your country though. I'm in the SW and stay south in the winter only venturing north when it gets warm. Both the inside and outside brackets are bent up so it has probably been going on a bit. I'm not sure what that angle iron is for or why it's just hanging loose but that doesn't look good and makes you wonder if there is more going on, if it was damaged being delivered to the dealer prior to sale or ?? One other thought is the open area cut out in the coroplast by the inside of the hangar. That's a pretty big hole. Has it always been that way? I think mine are all sealed with foam best I recall but I'm going to check mine when I get back out to the barn.
The 3 year structural warranty came out in 18 if I recall but don't know exactly when or when you got your trailer but maybe it would be covered by that. If they can't get you in you will have to make the call if you want to get it done yourself - Keystone might even reimburse you …..