And MW wasn't even the unit used in the source, the SAPVIA Solar PV Dashboard[1], which shows Megawatt Peak. MWp is a unit that refers to the theoretical maximum power output of a solar PV system (e.g. under ideal conditions.)

These data accord with the article's thesis, but it doesn't inspire confidence that units were conflated. They're not the same thing as megawatts, they don't measure energy, etc.

[1] https://sapvia.co.za/dataportal/dataportal-public