Apparently the report I saw was by a reliable daytime tv reporter even though NBC hasn't confirmed. I think the 3rd hour of Today has been a mess for the past year or so. They've gone through a number of co-hosts. And it seems like a lot of repeat of the first 2 hours with some added fluff. When I watched during the Olympics, they would interview the same athletes who were on earlier in the show. Today would be a good lead in for the type of content Megyn Kelly is going to have on her show.
As an aside, I noticed that the commercial that's been airing here in NY for the time change is from the local affiliate WNBC, not from NBC.
I also wonder if Kathie Lee may be gearing up to retire. She is a recent widow and I think her kids no longer live in NY. It may not be an immediate thing but I could see it happening in the next year or 2 and then Hoda can be moved up to the regular Today Show broadcast. Perhaps that 4th hour will go away entirely or if Megyn does well, she will get 2 hours.
To this day, I think nothing beats the chemistry Kathie Lee had with Regis. She and Hoda are good together but it's not the same dynamic.