It's true that most of those series are very, very white (WoT has a pretty diverse cast, though not really in the main characters). Which is fine in and of itself, but it's sort of a Bechdel-y systemic issue.
The problem of course is that if you change someone's race (e.g. black Siuan Sanche instead of vaguely Mediterranean) you'll have an explosion of angry nerds screaming about the SJW menace.
There's a whole thought process on this topic thats probably better for the Politics board. FYI I'm in the camp that says "if racial identity is important, then replacing one ethnicity for the other is the same social crime regardless of ethnicity".
I think once you get away from the typical blah blah conservative vs sjw dogma, philosophically it's a worthy discussion over coffee/tea.