Collateral freedom doesn't work in China. China has already blocked or throttled (hard to tell which, since GFW doesn't announce it) connections to AWS S3 for years.
They probably got an ultimatum from Chinese authorities to either stop allowing this or get blocked entirely.
They just blocked wikipedia last week.. no one is too big to get shutdown in China
Thinking about it the other way round, how likely would have Amazon been the target of similar attacks?
1: https://arstechnica.com/information-technology/2015/04/meet-...