It is not a 'perfect' fit but yes, it reflects South Africa's demographics a great deal more (significantly more) closely than does the DA support base.
Have a look at these for example:
An
IPSOS survey from 2013
that profiled the supporters of the three main political parties in SA (ANC, DA and EFF) according to language, income, levels of education, etc.
And here are the
South African demographics
And yes, it would be interesting to see the current supporter profile to assess what changes have taken place since 2013, given the continued dismal downward spiral.