I wouldn't be surprised if they wanted to do an Alien and Predator event but they've got a mandate that the game can't cross over with anything outside of its own canon/continuity. Because in the three or four years the game's been out they've done a ton of these little events, but not one that I can recall that's ever crossed over with another franchise like Fortnite or CoD or Fall Guys do.
Which kinda sucks honestly, and makes me appreciate it when some games just go "screw it, we're just gonna be a video game-ass video game" with that sort of thing.