Since the Third Battle of Seoul is fought between Dec 31 and Jan 7, a POD on November 24 only gives the UN forces a month to regroup and hold the line. Walton Walker died on Dec 23 and Ridgway assumed command on Dec 25. Given the disarray in UN forces because of MacArthur's attitude during the advance north, I don't think that's enough time to straighten things out.
Still, it's possible that the UN forces might hold the line at Seoul is Ridgway had more confidence that his forces would not be encircled and overrun. Perhaps taking over earlier would have done that. It would be a very close run thing. I don't think there is any obvious magic bullet here. It's certainly possible, but not with a high degree of certainty.