You should still be able to access content but you will need a new name if you want to play.

I had a friend who joined xbl on the og Xbox and let his subscription lapse. Then he got the 360 and signed up again but he no longer had access to his old email address for whatever reason and because of that he couldn’t reset the password he had forgotten and for security reasons Microsoft won’t change an account email address and password. So he lost his original GT and had to wait I think 8 years before it became available again and it only happened because ms said about midway through the 360 life cycle they were reclaiming any og Xbox gt that had never logged in on 360.

He was so happy to get his original gt back. This will also help get rid of names like thegamer10283737.

Most online services have a hard limit on days without login before you username is reclaimed. The only reason I ever log into flickr is because for years I paid for it and have a massive number of photos stored there and its easier to login once a year than to download them all. I think flickr has a hard limit of 4 years for accounts that never paid and 6 for ones that had but that could change if they get bought… Again.