Ok i know this has been talked about wvwr since the reveal/release of the anime, but here's my personal theory of the actual timeline if Sun and Moon, as i am one of the individuals that highly doubts that it is a continuation if the series that ran from johto through kalos. Heres my theory: SUMO isnt a reboot, its an alternate continuity.instead of going to johto,sinnoh,unova,kalos, he went straight to alola after his journey in Kanto,possibly the orange islands. This is why he still caught the Tauros', delia has mr mime, Team rocket can exist here,he knows brocl and misty,and has had tons of battles. Him knowing about mega evolution could easily be that he learned of it during some offscreen adventure, or that mega evoultions are more widely known in this timeline. Him going straight to Alola after his journey through Kanto explains his age and relative youtfulness,since hes only been traveling for maybe a year/only through the adventures of the first/original series. Also the fact that brock and misty are wearing the exact same clothes shows that not much time has passed between his kanto adventure and this one.