Does MCC have 4-player splitscreen?

Does it? I want to try it, but I don’t have 4 controllers yet

Until you want to play campaign (it’s 2 players only) there’s 4 players split screen for online pvp. However frame rate issues in some cases (H2A, H4) makes it unplayable even for 2 players.

Yes it does but don’t bother with it. Unless you’re only going to be playing Halo CE classic or Halo 2 classic, your game will lag like no other.

has this issue been fixed by now?

4 player spilt screen is available.

Yes. There is an achievement for play 4 player split screen Ctf on halo 1