It's "not BS" so no need to suspect that your dealer has some sinister plan to make your life miserable....
The "latest and greatest" from the RV door designers is a "friction hinge" that has a "dimple" in the female part of the hinge, on assembly, they "drive" the make part of the hinge into the female end, against that "dimple". What that does is provide friction "so the door doesn't fly open, exactly as your dealer explained it to you.
Problem is, as with most things in RV's, the "test and development" is done on customer's trailers. When it works, everyone's happy, when there's a problem, it's usually after the warranty expires and it's not a problem for the manufacturer.....
Right or wrong, it's "yours to fix"....
The easiest way is to repair your door "at home".
Take a look at this thread which started in 2013 (so as you can see this is not a "new" problem)
https://www.keystoneforums.com/forum...ad.php?t=10533
Look particularly at post #10. It's pretty much a "self explanatory fix" if you're somewhat handy with hand tools.