All RVs are not created equal when it comes to attaching things.
Some trailers have frames so light; nothing is safe to be added.
Some trailers have very sturdy frames because they may use the same frame on several trailer floorplans allowing some excess capacity on a lighter built floorplan.
Some "RVs" are motor homes with hitch receivers tow rated for thousands of pounds.
In ALL cases, you are ultimately responsible for 3rd party items that you add to your camper. Just because the damage caused by a bike rack may not be obvious, does not mean it is not happening.
Remember with a frame mounted hitch and load, the lever arm pivot is now at the rear axle attachment point. Flexing of the load is now happening there and not at the hitch. Just like a paper clip bent too often, eventually the metal will work harden and crack.
Lou, Laura, & Freya the wonder dog
2008 GMC Sierra 3000HD Crewcab SB Allison Duramax
2019 Flagstaff 8529FLS - Pullrite 3300
HAM CALLSIGN - KC3FFW