Window dressing? If they can't get a local to bite with those hours, they'll claim they've tried and employ an expat, using the advert as proof of having given the locals a fair shake.
Have to say, the Bots CPL students I've come across at schools in SA didn't strike me as the type willing to do the hard yards in the bush (not that Maun is serious bush work). I think a direct entry into the cushy airline career on big shiny turboprops was minimum start option among many of those I spoke with.