> They even admit to inspecting the IP address...
I don't think that sentence admits what you say? Chrome could be determining which experiments to run client-side.
Of course, when you visit a Google property, they needs must inspect your IP address to send a response to you, at a minimum. That goes for any site you might choose to visit. The existence of sufficient entropy to personally identify a site visitor is not a state secret. They do not need this chrome experiment seed to identify you, if that's a goal.