imo if they wanted the absolute best teams, they'd go for inviting:
nV + Selfless from NA
Riders + eUnited from EU
let ex-cyclone, misfits, dignitas fight for the final 2 spots w/ the others, but it's hard to split the eu teams with only a couple tournaments so far
plus seems unlikely that nV and selfless have been invited since nV have APEX games on 30th May and Selfless coach was unaware of invites yet. We'll see!