I think so. Anne Mae is a black woman who can credibly pass for Brazilian (which, in the play, is equated for whiteness). Olivo does this well, and I think Diaz would have been able to as well, were she given the chance to perform the role.
I would be very interested in her Gloria, though. Having seen her on stage before, I think it's a nice fit of actress and role.
"You travel alone because other people are only there to remind you how much that hook hurts that we all bit down on. Wait for that one day we can bite free and get back out there in space where we belong, sail back over water, over skies, into space, the hook finally out of our mouths and we wander back out there in space spawning to other planets never to return hurrah to earth and we'll look back and can't even see these lives here anymore. Only the taste of blood to remind us we ever existed. The earth is small. We're gone. We're dead. We're safe."
-John Guare, Landscape of the Body