I wouldn't think the box tube could flex enough to pop the paint off without any other problems. Not a materials engineer, but that is a **** ton of stress to not have any other signs of issues, especially given how relatively short the tongue is. I could see some flex over a long span, but the flex here would seem to have to occur between the coupler and where the tongue meets the frame under the structure of the trailer. I'd clean it, repaint, and add checking the welds to my pre-departure checklist.