Revives all dead players after the teleporter boss has been defeated, as there's literally no point for them to watch left alive doing their things. This won't, however, revive those who somehow managed to die after the revival has happened.
Simply place ReviveAfterBoss.dll in your Risk of Rain 2/BepInEx/plugins folder and you're all set.
This mod is server-side, which means that only the host needs to have it.
For any bug reports or feature requests you may contact me in Discord: _Simon#3851