The upside of this is that password managers don't need to adjust and you don't need to look up your password when logging in the next time as the existing stor

The upside of this is that password managers don't need to adjust and you don't need to look up your password when logging in the next time as the existing stored password will still be selected automatically. I always hate having to go through such things when sites decide that logging in through www.example.com isn't good enough and it needs to be login.example.com (and a year later, accounts.example.com)