I mean, in the sprit of Toriyama, Vegetto having an unknown timelimit because the Kai's are insular enough that they don't even know how it functions on morals kinda sells the upcoming "Universe 7 is dead last, even behind fucking Mad Max furries being overwatched by someone who doesn't even bother to take of his wife beater after he became the God of his universe". Its completely unintentional, so 100% in line with Toriyama's style. Also the OG explanation they figured in the manga was "Bad air" not "dark enegry". They had no idea why they defused either, and the most damning point, that Vegetto only existed because Gogeta got his movie in the middle of the Buu saga and Toriyama explicily didn't want to steal the movies thunder as he as said in interviews. Its likely the timelimit was always a factor for that fight, which was being written at the time of the movies production, so I find everyone bitching about it hilarious.