Pause is a menu option: "Virtual Machine" -> "Pause".
Definitely latest release of Fusion 10 Pro and this issue has been there for as long as I can remember, it's just never bugged me enough to seek answers. I started on Fusion 4 or earlier, although I can't confirm if it started that early. It's also been present with at least three different MacBook models.
Yes, physically unplugged makes no difference - as per my email above, even the built-in USB devices disappear. They only come back after Suspending and Resuming. Give it a try yourself.