The account was created in 2019, I wouldn't really call that a few years ago. In any case, terminations has not been run (apart from a manual purge in March 2020) since we started the migrations to DirectAdmin in December of 2019. I am curious as to why your account wasn't purged in that manual one though as it met the criterias for being so.
Due to the fact we're kind of in between systems there's no real way to terminate the account (it would also only terminate the hosting account, the base account that you login to the SSO page would remain). I can manually remove the hosting account, not sure I can remove the referens to it inside your control panel (the sso login) however.
As
@garrettroyce mentions there is also no way to create a new account at this time.
As for the forum account, it was automatically created based on the domain you chose when signing up. There is no option to change that currently available and I'd say it is probably not going to become an option either, short of creating a new separate forum account.