It wont happen, and there is a reason why. He is on a contract. I really doubt he will end his job on this manga when he always talks about how tired he gets writing it to end it in a stupid manner then start over again and feel very tedious about it even more than before, it wouldn't really make much sense.
Furthermore, there is too many advancements and things for it to happen unless everything just stops, which I dont really see happening for a while. DBZ was way more open ended and honestly after DB you could assume there would be another series. They're totally different shows/manga, it's kinda not really worth comparing until something different happens, right now they're in the middle of a war so lets wait before calling something like this xD
(If it did happen I'd probablllyyy go to Japan with a mini American Army and eat all their food D:<)