The "Suggestion" section doubles as a "Report" section, if you find someone ghosting, report them. It's also generally easy to spot out ghosters once they start doing it a lot. I think the command should be kept in for everyone. If an admin goes to someone in private asking them a question, how are they going to respond? There's a lot more issues that come with taking the command away than leaving it in.
Maybe restrict use of the command to Guests and make it so people who reach the first rank and above can use it, but even then, that's causing a few issues there.