Still true (the part about you needing to manually migrate mail to Gmail). My email server has changed and I’m no longer able to access it via what’s listed in the panel. I’d check Full headers of a recent existing message to see the actual server name.
When doing any type of email migration, it’s best to set up a forwarder to redirect your mail to a third party as you make the transition. Then IMAP sync your mail before you change your mail server.