Indeed, Morocco seems to be high on the priority list of LH, as SN has also decided to serve RAK and AGA as from next summer season for instance.
Those particular flights are for a tour operator apparently. I was thinking more in general terms of the Lufthansa's group African focus
Lufthansa -Route Network
Apart from the weekly Brussels Airlines flight you mention, bmi will be the only Star connection to RAK, so there could be some connecting flows over LHR to RAK supplementing local traffic