Users of MS SQL servers may find it useful to connect to their server via Windows authentication. The login dialog disables username + password in that case, as these are not required (indeed ignored by the server). The old option "Prompt for credentials" is now mutually exclusive to the new checkbox option "Windows authentication". Makes no sense to prompt for user+pass which then are ignored by the server. The connection dialog has grown a bit in its minimum height, as now the mentioned two checkboxes need vertical space. Well, features need space.
For MySQL sessions this checkbox is disabled. Although there is a MySQL server plugin
which allows Windows authentication, the difference to MS SQL is that MySQL still asks for a username - only the password can be blank in that case.
Thanks to csiqojerncjsa for the hint on how to enable "Integrated Security" in a TAdoConnection