If one region dominates this year

Will its league have more slots for masters/champions next year?

Don’t think so but I do not work for Rito

no.

region that does worst gets minimum 4 slots in events next year

Probably not. I imagine they would only consider doing something like that after several years of extreme domination. Just like in league of legends, china/korea had the same number of teams at worlds as EU/NA for the longest time despite being on a clearly higher level.