Do you mean Rover-3.2.1-rc1? the version that is in beta testing? Or maybe you're using the beta mission planner?
In any case, in Rover-3.1.2 (the older version) learning mode is still there but if you're using beta mission planner it may not appear in the drop-down list. If you use the official mission planner it should appear though.
By the way, in Rover-3.2.1 we've removed learning mode and rely just on the channel 7 auxiliary switch to save waypoints while driving.