Why are the Worlds matches 4 hours earlier next weekend?

Why are the Worlds matches 4 hours earlier next weekend?

NA viewers actually like watching NA teams play. The current schedule seems fair - it puts the games at early morning for NA viewers, afternoon for EU, and night for China/KR/TW. Great!

But next weekend the games are 4 hours earlier on Sunday and a few hours earlier on Saturday. C9 playing at 2AM, 3AM, and 5AM on the west coast is just not OK for NA viewers (its even worse for east coast probably).

Why the time switch? OK, maybe Riot had to get out of the arena on Sunday. So that can explain Sunday, but it provides no reason for why Riot switched the schedule on Saturday too. TSM is playing way earlier at much more inconvenient NA times on Saturday. It's 6 games on Sat just like this week, but its earlier for some reason, and those earlier time are obviously bad for NA viewers.

I mean, I get that the times are more convenient for Chinese/KR viewers, but I'd like to think that there is another explanation.