Of course, there's no reason why either character would have to be played by a white actor, any more than there was for Nick Fury or Heimdall or Iris West or all the others who have been cast diversely. But Hollywood has a track record of only changing the ethnicities of supporting characters rather than leads (unless it's changing leads from nonwhite to white, as with Starship Troopers, The Last Airbender, etc.). So going with Jaime Reyes rather than Ted Kord would be a better guarantee of diverse casting.