This has already happened a bajillion times over. Most often it takes on the form of "LOL RANDUMB COMEDY" or in some other cases "wedding diapers", "sports diapers", "diving diapers", there was even one nutball who spent literally YEARS on end trying to make "communion diapers" a thing.
Probably the most "successful" of all the attempted social engineering schemes that adult babies have come up with would be the college level "wear a diaper, duct tape your hands to a couple of 2 liter soda bottles (mix in alcohol if you like) and then the last one to keep from peeing their diapers wins".
Basically making a drinking game out of it… that's… that's the most successful form. There's been a number of variations over the years as well, but outside of college level sorority shit it doesn't usually catch on well.
The reason why you DON'T want to do this sort of shit though and the reason you DON'T ever want to try and inflict this or any other fetish on the public at large is that you will invariably attract and encourage the retard level class of adult babies to jump right on into the spotlight… and they will fuck it all up to the point of cringe level proportions. We're talking full on invisible dignity with some of the absolute worst of the worst the community has to offer being openly emboldened and enabled to the point of acting without any inhibitions whatsoever… so basically RainFurrest.
That's why most adult baby meetups and such don't work without at least some level of vetting to keep the worst of the worst out.