That isn't correct. Once the term of the subscription has expired, Pro Tools will cease, after a certain grace period, to be authorized...will not run.

If you have a perpetual license, with a 12 month upgrade and support subscription plan, at the end of the term, Pro Tools continues to authorize...you can still run Pro Tools. You will not be able to run any of bonus plugins (if you have any) and will no longer receive updates.

You are effectively frozen at the release and update that was current when your plan expired.