Korean league events S1 and S2 had the same period of distribution, and was done via Local Wireless, so there's nothing suspicious there
For most of previous pop-up shop and league events, the event only ran during the physical event was there, which only lasted a couple of days.
IIRC Most of Korean physical event distributions have been some kind of port/mirror of other events.
Before the Korean league SX events, the mirrors were usually Japanese Pokémon Center events, but now they're branching to Western events being mirrored too ><
edit: archiving the page for now.