Good news! Starting July 11, you’ll be able to play Halo Infinite online with up to three friends as part of a beta test. And even better, you’ll be able to replay missions from the campaign, too. However, here’s the bad news: This is a limited-time test of only 10 days. And you’ll need to restart the entire campaign…
Source: Kotaku – Halo Infinite Co-Op Testing Starts July 11, Also Adds Mission Replay