No, a dead sub stays a dead sub.
You don’t need to do anything. Dead subs will “float about” in the list for about 10 days and self disappear
Not Active (ie: enabled) subscriptions (auth revoke/dead for another reason) don’t count to your active subscription count/don’t block subs being created
Just make subscriptions when they authenticate.
In some cases/applications I try to make subs everytime they auth and ride the 409 conflicts out 