Well, out of many tens of thousands of trailers shipped over the past 10 years, a relatively small number have reported problems with the upper frame structure near the pin box. It's usually described as frame flex. It's a relatively rare condition, but it does happen. There's also the occasional problem with side wall framing, but that's much less common.
It's notable that Heartland has repaired frame flex problems at no charge, whether in warranty, or even many years out of warranty.
The nature of forums is that people mostly post about problems, and then there's often a lot of discussion about the problem. It can seem like someone is reporting any given problem every day, when it's usually the same incident being discussed by a number of people over a period of days or weeks.
Your likelihood of having a frame problem is very low.