I'm very sad to hear this. But apparently Valve has announced Chinese major streaming websites officially.
Including Bilibili, Acfun, Douyu and Huya, those are the four streaming websites with most viewers in China I believe.
Valve has asked them to make all the independent streamers set a streaming delay while watching any Ti 10 matches so their "live stream" would actually have 15 mins latency compare to the "official" channels.
First I thought this is a global policy, but after I visit Gorgc's channel, it turns out twitch has not been announced.
Very disappointed about this regional policy against China.
Ti 10 should be a players' event.
Source: official social media accounts of websites mentioned above
Sorry for the pictures, they may be oversized for some people.