Question about Microsoft Xbox One X

Yes, all Xbox One controllers are compatible. Xbox 360 controllers are of course not, but all Xbox One controllers are:
-The very old ones without headphone output
-The newer ones with headphone output
-The Elite Controller
and the Xbox One S controller with Bluetooth

Unfortunately, I have to answer the second question in the negative. No one can play Fortnite with colleagues on the PS4, except other PS4 players and PC players. Unfortunately, Sony has disabled crossplay with other consoles, so that means the Xbox One and Nintendo Switch can't play with PS4 players. Simply put (does not apply to Fortnite):
In a group can be: Xbox One, PC, Nintendo Switch
or: PS4 and PC
but no combination of the two. As soon as PS4 is included, Nintendo Switch and Xbox One users are excluded.
I hope I was able to answer your question.