Adam Yes, it would be like that.
Just for consideration, I can do that in a cPanel account. The "Check Email" button automatically logs you in to the webmail for that mailbox and any you've created.
I see how it could be kind of a privacy issue for some people, but right now phpMyAdmin works this way for any created database. I'd believe it would be the same kind of exposure.
Maybe there could be an optional setting to turn it on and off.