Has something changed in the Apple/iPhone environment recently in regards to phones attached to accounts ?

I've been sent two iPhones for work to be reset and given to new users.

Previous users have removed the phones from their accounts and done factory reset - yet both phones ask for passcodes yet neither user put one in.

One does mention its still attached to a particular account altho the user swears it was removed but the other just asks for passcode with nothing else.