There was indeed an Irish Mimi-and many other changes to the original 'types' in 'Rent Remixed' there were many reasons that production didn't work, but the race/nationality/accent/whatever of the cast wasn't one of them.
I think producers/casting directors do tend to stick to original cast 'models' unless they are trying to do something different (as above) personally I don't think it's wrong, perhaps a bit lazy but not wrong.
Maybe I'm on nobody's side
http://phdconfessions.blogspot.com/