I'd wager it's just an extension of the beliefs everyone's been holding since around Steve's era. The Bamco Miis starting showing up separately, and were the first to come back, so everyone started looking at Lloyd funny. That, and we still haven't gotten another Bamco rep since Pac-Man, so some felt like we just won't get another Bamco rep. Plus, Yuri means we can get both a Tales rep and the Lloyd Mii, so people started latching on to him.
Meanwhile, Rise served as a wake-up call for how big MH was. It was always huge in Japan, it had recently hit it big in the West, Nintendo was heavily promoting Rise, and it already had base game content, potentially fitting in with Second Chance Theory. Monster Hunter quickly shot up to become one of the big "safe" options, and everyone started going for them.
Really, I think the two swords thing is just a reason to go with what everyone's already been expecting for months. Though, by that logic, the MH Miis should also be returning because there's two Miis and two fighters.