but if they're not filtering BGP announcements for those ranges (however unlikely), and the GFW isn't blocking traffic out to those addresses (even more unlikely), and the internal metrics were high (super unlikely), I guess it'd slurp out all the traffic? maybe this was a weird smash-and-grab.
You'd be surprised, but GFW is a blacklist not a whitelist, as such the blocked domains and/or IPs are a very small subset of all public addresses out there.