QSuite planes are likely prioritised for markets that attract higher revenues (US, UK, Australia...) and where there is significant competition so that QR wants to have a leg up. African markets are not likely to be at the top of the list. I haven't heard anything about plans for existing 77Ls being upgraded to QSuites; but I wouldn't be the one to know much on this topic. This thread might have more info:
The Complete Guide to the Qatar Airways Fleet