What exactly looks suspicious (beside him waking up after few years break) as a change of email and password is not much of evidence. Has he changed the boards where he is usually writing, or maybe his post quality suddenly changed? You should put a little bit more effort and analyze his activity before asking others to check it out.
I have seen you have mentioned by a neutral trust that possible change of the account in 2017. But I have not got a clue about it. The first-time password was changed on at 10/18/2022 5:56:16 PM and woke up 10/18/2022 5:55:27 PM. But if ownership changed then the password should be changed too at the time of ownership change!!