Is crossplay available for Halo 2 in the Master Chief Collection?

Crossplay appears to have been added on November 17^th, 2020 for the game. Here are the release notes on Halo Waypoint:

• Crossplay and input-based matchmaking for multiplayer are now available on both Xbox and PC While players will be prompted to select their preferred input device upon their first launch of the game, this option can also be changed at any time from Settings menu while in the Main Menu

It seems to only be limited to that of multiplayer game modes (no compaign crossplay).

Other sources:

• Shacknews
• Gamespot

Both of these also cite the original Halo Waypoint source.