The alleged locations are:
Americas: LA
Asia / Oceania: Seoul
EMEA: Berlin
where would you like each league to be operated? personally, i think the Asian / Oceanic league could be somewhere a bit more central i.e. Thailand or the Philippines
LA will always be the home for Riot's esports in NA, they definitely won't change this, they might make a LAN server for the event though
Seoul, while not the most populous region for VAL Esports, like LA, it has a lot of the infrastructure from League. Also not too crazy visa-wise or CoL(Cost of Living)
Berlin also makes sense, home of Freaks4U, the production company for EMEA.
Americas: Logical since LA is home to Riot's main office anyways. The LCS is headquarters in, a lot of Riot's infrastructure already centralized within LA.
APAC: Yeah, logical too. You can't count out Seoul as the esports powerhouse. While they are using the Sangnam Coliseum (former OGN studios), I can imagine LoL Park as a possible venue as well.
Berlin: Again, logical. The LEC has its studios there and Challengers EMEA also headquartered themselves in Berlin.