I would wonder if Mike has some short monologue at the beginning of the first episode he taped. Seems entirely possible, and something that would have to be edited out to save face for everyone.
I was in the middle of a move when LaVar Burton's episodes aired, and the worst that I heard was that he was a little wobbly. My recollection was that Alex was that way in the early episodes as well. In LaVar's case, he only had one taping day, and stuffed into the most ratings-challenged week of the year. I've always felt LaVar could at least be a good transition host for a few years to maintain the gravitas Alex brought to the show.
Mike really blew his real chance, which is to host Wheel after Pat retires. He would have been more suitable as Mr. Game Show there. In an alternate universe, he would still have to address things from the past, but it's unlikely that it would have really scuttled his chances, and there likely would not have been this level of scrutiny (unearthing old podcasts, for one) for that job. That said, how do you not disappear that podcast!
Although it is not the be-all end-all, it is amazing how within a year of assuming control of an American institution that he managed to royally piss of loyal fans. Twice.