As the first course I ever played, on a Monday when the course was closed, and for which a disgruntled pro sat behind the then 17th green to present us a bill for our transgressions, I have always had a soft spot for Medinah that others don't share.
As much as can be told from plans and renderings, I like the rerouting. It seems to be of the "only fix it if it is broken" variety, which seems like a good mantra for almost any renovation.
The course had snap doglegs (originally) on 9, 11, the current 15th original 13, and 18, which Rees had somewhat removed, but the tee across the pond is much better than having to build one on the reverse downslope where it was. The old short par 5 or later long par 5 with the Eleanor's Teeth green was never anything special. And, while long gone, the original 14th par 4 was a cliffhanger and the water wasn't in play, thus nothing special either.