Yeah, it could very well be something that took a little bit of time/use to wear down to the point of concern. Whatever it is, the general rumor (and I can't stress it enough, RUMOR.) seems to be focused on an issue with the trains.
The only thing I do know is there were reports of a lot of rollbacks when the trains were trying to clear the hill, and that the cushions for the wheel bogeys are pretty small compared to the heavy-duty fat ones that the Intamin trains had.
Either way, it's a big wait and see on whenever the coaster will get back up and running, and when it does, if there's any visible differences to the trains, as that'll probably give the best insight on what the issue was.