No, only quickplay, which is everything goes. Competetive is blocked crossplay.
Edit: I know because we tried it with people on xboxes and it didn’t let them compete
From what I understand this is more about controllers being so bad for this kind of game that console developers regularly build in cheats like aim-bots officially, so why would it help if you connect a controller on your PC?
I play with controller on PC but I don’t play competitive but honestly… I don’t want to lol. But they should let us play together in competitive. Guess I won’t bother with it cause I like to save my wrists for actual important things on kbm otherwise I have carpal tunnel issues. It would be cool to see controllers on leaderboard with kbm. Gyro aiming is pretty good these days too.