I had just booked a tour of the Colosseum/Forum/Palatine for November, then got a call from the tour company about the third level part of the tour. It seems that the Colosseum has now split up the tickets into one for the underground/arena floor, and one for the third level (and maybe fourth and fifth levels if those will stay open), but they still charge the same amount for the underground as they did for the old underground/third level ticket. This means the the tour company has removed the third level from their tour and will do something else instead, some exposition or something. I didn't ask for details because my main interest in doing a tour at all is for the stories about the Forum and the Palatine Hill.
FYI in case you're looking at tour tickets starting in November. I suppose all this could change in the next couple weeks, but might be worth checking on if you want to do a tour and have your heart set on that third level.