User counts for licensing is based on the status of the user profile, so if the user has used the system before (i.e set up their authentication for resets) then a user count would be used.
Deleting a user would clear that, but disabling a user would not.
You can reset a user's profile state though by clicking the + next to a user and selecting Reset Profile (it's also possible to do this in bulk if needed).
Chris.
