How to remove not longer wanted or existing Teams Accounts without logon
If nothing of the following actions helps:
Windows Settings -> Accounts -> not visible in Email... or Work ...
Control Panel -> not visible in Credential Manager
Settings App -> Apps -> Teams -> More Options -> Clear Cache and Reset App
End Teams Processes!
Start Explorer -> Press CTRL+L -> Paste (CTRL-V) %LocalAppData%\Microsoft\OneAuth\accounts
Open any Files in Notepad or desired Editor
Delete the Files containing unwanted Accounts
DONE
Start Teams and enjoy