If he were to no longer host, he would still need to remain behind-the-scenes as producer. If not, the show is going to turn into something very different. Whether it will be better or for worse depends on the replacement.
I certainly would be very doubtful that I would still like the program without Probst.
"The Spectacle has, indeed, an emotional attraction of its own, but, of all the parts, it is the least artistic, and connected least with the art of poetry. For the power of Tragedy, we may be sure, is felt even apart from representation and actors. Besides, the production of spectacular effects depends more on the art of the stage machinist than on that of the poet."
--Aristotle