So according to the HTC South Africa Twitter page (@HTCSouthAfrica) the HTC10 is undergoing local network testing and they are aiming to launch it in SA in Q3 as per the 2 tweets below... Hopefully it will be available before August because that's when I'm due for an upgrade 
https://twitter.com/HTCSouthAfrica/status/743705678573801474
https://twitter.com/HTCSouthAfrica/status/747827674534510592
https://twitter.com/HTCSouthAfrica/status/743705678573801474
https://twitter.com/HTCSouthAfrica/status/747827674534510592