Every now and then = a average of one per year.
WWE is comfortably numb in it's position and John Cena is at least established as a kids star like Spoungebob or something nowadays. They have no incentive to take any risks or do anything to make lots of money. It's not like the mid 90's when they were pushing out goofy characters and had competition to push them to the extreme.
PPV numbers are worse than they've ever been, ratings are as bad as pre Attitude era, but they're a developed brand now - so they at least make a lot of merchandising and license fees, and live gate money. They won't risk that by becoming less kid friendly trying to get mainstream popular again. And even if they did try it, it's probably too late. The mark crowds nowadays don't know anything about wrestling's past. It's an awkward blur nowadays, Vince has effectively killed the ties to the past for the most part. Any "legends" brought out from behind the scenes just gets a laugh for being an old man in a costume.
You can just do what I do, passively watch while doing something else, or just skipping a show entirely not giving a fuck. I still like to root for bad news to happen, so eventually the news will become bad enough they'll be forced to change, but it's probably several, several years before this occurs. It would take Cena not being in the business for one reason or another to hit the kid base hard.