Mike,
It disappeared because I made it disappear.
The default setting for the "Show in menu bar" option is now "no," while in earlier versions of QRecall it was "yes." To make the menu bar icon reappear, launch QRecall and go to QRecall > Preferences > Monitor, and check the "Show in menu bar" option.
The reason for this change is the new "Show in dock" option, added so that the QRecall Monitor can interrupt a restart or shutdown request if there are running action. Since the dock icon duplicates all of the functions of the menu status bar item, it made sense not to have them both showing by default.