Eh, I can't agree with that. It's true most everyone
eventually falls in line with one ruleset, but it's less for idealistic purposes or truly agreeing that one ruleset is the best one, and more for practicality, players want to be able to practice for big events, and if you don't have the same ruleset as the big events in the region, they either A. might not go because the practice will be inadequate or B. the event may not even count for the regional PR if it differs to much from the norm, both of which disincentivize using opposing rulesets with a few exceptions (Mainly stuff like banning Doubles Cloud that a
vast majority thinks should happen). Then of course you'll also have the big regionals deciding to follow the biggest tournaments even outside of region because they don't want their region's players to be ill-prepared for those events. Also, there was that big huge poll in which the majority voted to legalize Guest XXXX Miis, and numerous other polls after that pointing in favor of Guest XXXX over Guest 1111, but Guest 1111 is still the standard because the ruleset committee didn't/doesn't agree with those players' opinions. (
Source Ctrl + F or find "The Public Opinion on Miis in Smash 4 " and read from there)
What I suspect will happen is that there'll be intense debates on what to do with the stages, and regardless of whether or not it's popular or not, some big tournament will choose one of these, and many smaller locals and regionals will follow suit, but this won't change people's opinions on it, there will be some that love the ruleset, and some who hate it, I doubt there will ever be a above 70% majority that agrees on one ruleset being best, most people will follow one, but I don't think that's truly agreeing.