Flex is not the same as normal? Funny you say that, because it's going to be named normal in 6.0
Flex *is* the nerfed version of normal mode like ICC/DS. Blanked buff to normal modes would be the equivalent of giving normal mode gear in flex, absolutely zero point.
People always said "if you want a challenge, remove the buff".. well, if you want a challenge, do normal instead of Flex.