Eh, I like it. It adds an extra dimension to his becoming the Red Hood and ties in with the Red/Black conflict that has gone throughout Morrison's Batman run.
Besides, look at it in these terms: to people unfamiliar with the original origin, it's just a small new detail that fleshes out Jason's resentment of Bruce and, as above, adds a new dimension etc. For people who are familiar with it...it's just hair colour! I don't see why it should be that big a deal.