Other possible upsets
X10 could beat NV (insider sources have told me NV look significantly weaker in scrims since masters 3 while x10 look a lot stronger)
Sen vs Furia (Furia have sucked balls in scrims but sentinels have been steadily declining)
C9B vs. FNC was just series between somewhat equaly strong teams, where C9B were not viewed as favorites(nor FNC), at least from a historical and statistical point of view. So, calling it an "upset" is wrong - just correcting you here. On the other hand, the other two matches you've listed have a clear favorite in them, so there are possible scenarios of an "upset"