>>186258052019 eh?
The problem here is that due to how NJPW contracts worked, Kenny would be in an awkward spot as the Mania card was largely penciled in and done. He'd be thrown in some nothing filler match, like AJ was. Which is a hellacious fumble. There's no room for shit in that mania card, it was jammed full.
Now I can see him coming in RAW after Mania. That gets everyone talking, gives him plenty of time to recover, rest up, and learn the WWE style. He has his big PPV debut for Summerslam vs some big established name. Maybe straight up hotshot him with a title feud vs Seth. They'd work the rest of summer. In fall, do the fucking tag team up. Kenny turns heel in survivor series. Sets up HIAC vs Seth. We avoid that godawful seth and becky feud vs corbin and whatsherwhore. No seth vs fiend.
Now what? Fumbling time. He inevitably gets fed to the Fiend/Brock/Reigns, and he's perennially upper midcard for the rest of his time there. Sure, he'll do amazing matches vs AJ and Finn and the other world class talents that end up doing fuck nothing because Vince. He also spends much of his time avoiding Vince, because Vince wants to give him a Pacman Fever gimmick. Eventually released in like 2022 and goes to AEW and nothing really changes. Hangman is fucked though.