If Disney buys Fox, there could be three outcomes. One, Alien and Predator would be made PG movie, like MCU movies. Two, the two franchise would be deleted or erased because of it's non kid-friendly traits. Three, Disney would try the R route, which may or may not hurt their reputation as a family friendly franchise (well, maybe, as there are many guts and bloods. Cursing may contribute a little, as Falcon said "shit" in CA:TWS and little to nobody complains).