They only asked black players/coaches to sign the letter, so we shouldn't draw any conclusion from the fact that AB, Faf and the rest aren't on the list.
There is more at play here though. Off the top of my head, Ngidi faced severe criticism from Dippenaar, Symcox and McMillan for his opinion. The fact that international players have such strongly misguided views shows that racism is far from anywhere being solved in South Africa.
In addition, there are also subtle factors like the current administration having free reign to bring in people they know without any serious vetting process while the previous head who was hounded out on charges of corruption and mismanagement has still not been proven conclusively.
Adding on to that, the interim coach was criticized for looking out of depth on a tough Indian tour while Boucher has escaped criticism and garnered sympathy despite losing a home series to an English side that suffered from illness.
https://www.planetcricket.org/forum...south-africa-launching-new-game-format.114831
