Re: some of those being asked back were apparently laid off by mistake
If I had any passwords I’d destroy them to make sure I can’t be accused of doing or planning anything naughty.
(Actually, I handed over computers and backups with all passwords changed to 1234. And for one account that hadn’t been used and nobody knew a password, there was 2FA connected to my private phone, so when they recovered that account, they had to call me and I read the 2FA code over the phone to them).