I was talking to Loss about this and his feeling is that in AEW the people make the belts as opposed to the belts making the people. That said you can only end Miro's dominant reign for the first time once. If they were to have Kingston beat him and then him win it back, the way to do it would be to add something to his act in that second encounter to heat him back up (akin to how Diesel debuted to help Michaels retake the IC belt from Jannetty), like, I don't know, CJ Perry.