My speculation: as Sep. 3rd, the massive military parade in Beijing draw closer, Chinese government appears to be knocking at open source developers' doors, asking for repo removal.

This can be linked to previous takedown of shadowsocks, see this hacker news thread: https://news.ycombinator.com/item?id=10101469

Updated: and DDoS is an option too, https://news.ycombinator.com/item?id=10115513