I’m all for adding some diversity that wasn’t as commercially possible when these characters were originally created in the 60’s and appealing to a global market. I also think it would work well within the context of dealing with prejudice and bigotry that the mutant concept is founded on.
My only regret is that I really love the holocaust survivor origin of Magneto... it’s very powerful and served the themes well. But with the MCU being set more or less in “real time” I think that’ll regrettably have to be jettisoned no matter what in favor of casting a Magneto who is less than 90 years old!