Structurally it should be fine. It’s almost definitely aggressively screwed into framing.

They’re a retake nuisance to install many fans on for a couple of reasons though. I’ve never had good luck with fans that had big radio receivers that come with remote control fans. There’s just too many wires to fit within the space of the pancake box.

Technically, according to the electrical code, that 4 inch pancake box is too small to accommodate 3 conductors plus ground, but it’s a bit of the code that’s routinely ignored.