If “Josh” was put on hold by the moderators and/or quit, why is he still active as user159691? (And its clearly "Josh" from his answers on ELL.)
Deleting a profile and quitting Stack Exchange are two different things, because people can have multiple profiles.
The only Stack Exchange policy on multiple profiles that I know of is that they cannot be used to “cheat” – cross vote, for example, or avoid a suspension.
Multiple profiles are useful, not just for technical reasons (such as testing, or organizing one’s tag subscriptions), but for social reasons. Multiple profiles allow a user to project different identities. For example, a person might wish to safely ask about something with a stigma, or otherwise raise a question that might result in an injustice if it was known who asked it.
So it is nobody’s business whether
user159691 are the same person unless there is cheating involved, and nobody in a position to know will confirm or deny it.