I'm pretty sure the new p90 is legit. I was in a game yesterday with a cheater who started spawning guns. Saw them on the ground and people said they where p90's. Looked like guitar guns from afar but the game ended before I could try and pick one up .
The P90 CBS was a event for German users, if they'd bought something(forgot) they'd get a CBS cap (Very similar to the black hat when you get as soon as you start playing Aombat Arms) and the P90 CBS for 30 or 90 days.