John Cena was actually the executive producer of Keep It Spotless, not the host. He didn't appear on camera. Now that John Cena working on another show, it hints that Keep It Spotless is already cancelled.Yep, as well as the host for the KCA of I think 2018!
Also, The NickelodeonPress site has updated with a few of the new shows announced! Here is the page for Are You Smarter Than a 5th Grader:
Nickelodeon’s new Are You Smarter Than A 5th Grader follows the original premise of adult contestants putting their knowledge to the test by answering questions taken directly from elementary school curriculum. New game elements will be added to the show, including an additional “cheat” option...www.nickpress.com
Let's not forget he was also host of KCA 2017 as well as 2018