I can't address that lens specifically, but think twice about a 70-200/2.8. It is big and heavy, even in the backpack. If you need the 2.8 aperture, then it's a great lens. There are three compelling reasons to consider a 2.8 telephoto zoom:
1 -- Maximize background separation. particularly for portraits
2 -- Low light, when you need the extra aperture
3 -- If you really need to maximize shutter speed, for sports. Where you need to shoot 1/2000 in mediocre light.
But for daytime safaris? I don't see the need. You could get a high quality 70-300... it would weigh less than the 70-200/2.8 and give you more reach.
You could go with a 100-400 or 150-600, size will be similar to the 70-200/2.8, with a LOT more reach. For a safari, telephoto reach is a higher priority than fast aperture, IMO.