If one reads back a bit, tour companies have standard block-bookings for a range of accommodation. This precedes the normal public bookings time -wise...don't care what SP says!
If they don't fill it, which is obviously often the case, they lose the deposit on leftover units a certain time before pitching with the rest. Theoretically, at least. Personally I believe they don't lose anything, and even if they do, they would obviously book at base rate occupancy, ie 2 per campsite or unit, which could house as many as 6 tourists should their customers actually be contracted...they don't know either, more than a year in advance?
So losing a deposit of half the amount for a base-booking is not the end of the world for them, and they probably don't even bother cancelling before their deadline is up, as customers may still enlist a day or two before the date anyway.
They make the real money off the hospitality side of tours, not the accommodation!
Another thing is that camps report a constant number of units "under renovation", hence not available for bookings...which has been alleged to be a grey area, and needs to be audited.
All above is why one has a tremendously good chance of getting accommodation in a camp on a 24-hour basis, just pitch up and stay within cellphone range and enquire constantly!

Please check Needs Attention pre-booking: https://africawild-forum.com/viewtopic.php?f=322&t=596