As far as I can remember the fact that SAX is now on the books of Transnet is a recent development. Originally on SAA's books. Government will probably take SAX back, but this is all smoke and mirrors/creative book keeping.
The only way govt. can shed expenses is to hand over business units to private enterprise. Such as the recent acquisition of Transnet housing by FNB.
I always thought that SAX should have been South Africa's next low cost carrier years ago, way before Mango, by simply rebranding and adjusting the business model. Interesting times ahead.