People are failing to realise that what keeps a game alive is a strong multiplayer.
Once everyone gets tired of the campaign, like its already happened with alien isolation and also but long ago on avp 2010, it's up to the multiplayer to keep the playerbase strong. Happened with avp classic and avp2 in similar style to most of the arena fps at the time, while on avp 2010 MP was bs, uncompetitive gameplay, poor shooting mechanics, killing moves, etc, resulted in a multiplayer that is total rubbish. This is mostly in part because of the console players, as no studio would discard that part of their market share and make a pc only game, so thats why no SDK and no arena fps and instead we have "press X for killing move" unmodable shit.
Start putting out avp games that once again aren't aimed at a 5 yo console player and we can start expecting a game that lasts more than a few months before it dies. But we wont see any of that soon, because studios want to make quick cash in pre-orders from both conosle and pc players and not spend much in server maintenance so they would rather let morons pay before release and let the game die after a few months. It's the obvious choice if you are running a business