In this specific case and in general, you will only get the possible carriage return entry with the question mark prompt when you have reached a specific instance of a list entry (the user list in this case). If you continue to tab to the next argument in the command line as follows:
localhost(config)# no aaa authentication users user ?
admin oper private public <cr>
This is the standard behavior of ConfD’s Cisco C-style CLI. What you are suggesting isn’t currently supported.