The limp and the cane will always be a part of House's character, because the missing muscle in his thigh can't be replaced by any treatment or therapy. So the most that the writers could do, in the real-world version of Houseland, is take away or reduce the severity of his chronic pain.

Still, even if they don't go that route (and I agree with you that they probably won't), I don't see how it invalidates "No Reason" in any way. The point at the end of "No Reason", IMO, is not that House is going to get rid of his pain, the point is that for the first time he's willing to try getting rid of the physical pain even at the risk of dimming his mental brilliance. The willingness to take the risk is the important thing in terms of the character, not whether or not that gamble turns out to be a successful one or not.