I just created my characters on the MDI and AWC tournament realms for the upcoming time trials and Cup 4, respectively. When I swapped back to Dalaran so I could log in to grab my Edit Mode profile, my entire character list across all NA realms, as well as my previously-assigned Warband favorites, had been completely jumbled. The jumble was so bad that most of my actually active characters were pushed to the bottom, while a bunch of characters I haven’t played in long enough to make Gear Updates available to them were brought to the top. It was as though the list was flipped on its head.
Restarting the client proved that it wasn’t just a temporary display issue; the jumbling really happened. It also did take creating a tournament realm character for this to take place, as simply swapping to those realms had no effect previously.