This post is not to address this specific OP situation but to inform on other site policy activity:
We used to purge accounts that hadn't been accessed beyond a certain period of time; we stopped that practice a couple of years ago. To wit, we have no member (active, inactive or banned) in the member database with that userid.
For the record: Something I started doing a couple of years ago was checking out EVERY new member account's login data again our member database (and other external sources which I'll keep to myself). If something looks questionable I'll call out both member accounts for it (had a couple of members who are coworkers get called out recently. Both were a bit displeased with me). This practice helps keep people from creating more than 1account as well as keeps banned members from re-registering. If a member goes inactive for a while, their account is still available to be found for this check & I let them know what I suspect is going on. Their reaction to my PM, even if positive tells me more than their words alone. Like HBAR said, speech patterns are familiar. It's not 100% effective, but much better than nothing. The chances of successfully creating a new account by a banned member or someone who is pulling a fast one is slim at best. Often times I ban if my spidey sense is tingling too great. All of this helps stop the scenario identified above.
There is a reason my user title is "Roger's Revenge" (an ode to the site Founder & original owner) and my avatar is the Ban Hammer.