We have registered another account back in 2014 named "eXch" which has no posts and was locked due to inactivity, however we still have its password:
https://bitcointalk.org/index.php?action=profile;u=317539Your account is locked because it sat inactive for years after the password hashes were leaked in 2015, and was therefore at high risk of being hacked. Email reactivate_2019_bgbs5[at]bitcointalk.org to get it unlocked.
Maybe the forum administration will consider deleting that account to rename this one.
Why not consider unlocking that account instead of requesting its deletion? Given the account's age, there might be some value in doing so.
I'm not sure about the exact requirements and what needs to be done, but have you tried sending an email to the provided address?