Fast forward to now, and it turns out they were a scam after all.
Back in June they started sending me notices about not having paid a fee for “Maintenance”. They threatened to shut down and erase all my stuff at some unspecified time in the near future if I didn’t pay up. Although the fee was small, it seemed like a violation of “free forever”. Since I didn’t have much important stuff and their service has always been crappy, I let it slide.
No more throwing good money after bad.