When a pvp outage occurs ie: " no dedicated servers are available" or “unable to start dedicated server” the cause of said issue like an outage would be preferable to people thinking they are banned.
If a user was banned they would see a message specifically stating that they were banned from matchmaking, any error messages relating to server issues mean just that - there are problems with servers. Right now it’s the case that servers have issues. 343 are aware of those issues and are investigating, you can keep up to date by following this thread: https://www.halowaypoint.com/en-us/forums/e0d9938206f04a598ce84f2c8cadce02/topics/343-response-can-t-access-halo-servers/645c3885-9167-4864-a8a3-ba234ca6ef04/posts