That’s incorrect. Fortnite was detecting and blocking digital movement to prevent their own native m/kb players from entering console lobbies with a controller, then swapping to m/kb on the bus.
It only lasted about 5 mins after landing, and was only a implemented for 2-3 weeks before Sony informed Epic they were blocking licenced devices like Hori Tac Pro. Epic was in breach of the Sony TOS, not XIM & similar devices.
XIM was never the target and was never detected, it was collateral damage. XIM easily bypassed the issue by creating SAB to more closely align keyboard movement with expected controller input.
XIM cannot be detected at the USB level by any operating system because it appears as the controller connected to it, so PC isn’t blocking XIM any time soon.