I'm the LAST person to ever complain about newer stuff "ruining" older stuff, cus it doesnt... but something does bother me if it's a new mewtwo.
Mewtwo always seemed like a sort of abomination, you know? Extra powerful, but still a deformed-looking version of the original. So it doesn't make sense to me that a new mew clone would have the exact same anatomical structure as the old one. I'd almost rather the new form just be it's only form, since the mutations would be different. Maybe they would be the same though, if the exact same genetic engineering data was used or something.