It's been a few years but I'm sure there were JHB-Skukuza flights, I'll let someone here who has been there more recently comment on that one.
SAX used to operate JNB to Skukuza. When MQP opened they were asked to stop operating there to help the new airport get off the ground. The idea was to resume into Skukuza by 2009, but now the Provincial Government refuses, because MQP would become a white elephant......