When you say disappear, as in no longer possible to play that campaign?I'll echo Titanfall 2 for best single-player campaign.
Destiny 2 is free and like others have said has some great gunplay. If you do go for it you need to go to a vendor called Amanda Holiday once you get to the Tower social space to start the 'Red War' campaign which is the original Destiny 2 experience.
They made it optional when it went F2P so you could jump straight into multiplayer GAAS type stuff with friends without having to go through it, but its a good singleplayer experience.
It's also going to disappear come November 10th when the new dlc comes out and they streamline the game by removing some older content.