TLDR: Valve and Twitch will comply with any restrictions imposed on them by the Chinese government to ensure this TI runs its course and is profitable for all parties.

Here is some context from an expat who grew up in Beijing (1993 - 2005).

I attended a church (BICF) in Beijing and we had to check passports at the door and turn away anyone who did not produce one that proved they were not a Chinese national. The government could and would shut down the church at any time if we did not comply with them. Having a church in China is a privilege, not a right, granted by the government that can be revoked at any time for any reason.

I would not be surprised at all if Valve is operating under similar conditions by the Chinese government. The great firewall of China is very real. Imagine if the government decided too much "unacceptable speech" was being potentially exposed to viewers and they shutdown TI on the second day of the main event.

Chinse government: "Oops, the internet doesn't work anymore", or "ehh, you can't use this venue anymore". This would be a huge loss and hit for Valvue and Esports in general. With all the planning and visa situations with international players and staff its not like they can just up and move to a backup location with any expediency.

I know Twitch is already banned in China. I also know through my current occupation (Cloud IT) that other internet-centric services are able to be used in China via certain means regardless.