Based on what I know RIOT take org that
- have easily to get reach and big FANS
Ex : DRX, Gen G , T1, Crazy raccoon (yeah don't ask that), RRQ, Team secret, talon, GE. - Zeta and prx I remember not that big based on fan but the player itself have potential to take advantage with EMEA and NA .
Riot see potential this 2 org for make new ppl who only know val get another new fans on this (win win solution)
Note : this is just from my perspective