Halo Infinite co-op campaign beta started earlier in July and players are excited to try the new co-op system finally. There are a few minor issues understandably, but there is one serious point aside from all minor problems. Halo Infinite co-op mode does not have matchmaking.
You may think that it would be a beta-only situation, but unfortunately this is not the case. Developers confirmed that there will not be online matchmaking for the co-op mode. They stated that they want players to use Halo LFG and the new Discord voice call feature to find players for teaming up and playing Halo Infinite in co-op mode.
Xbox and Discord integration is a recent change so they want to understandably test it live, but the way people can find party members by using Discord channels or Halo LFG website is definitely an extra struggle. If you have friends around already, you will not see much issues with it. If not, this may take some effort.