It also accesses
snapshot.debian.org when building new images, so the traffic should be pretty small: it is just a tiny handful of developers, plus the CI system. End users download the binary that was build and published by Google.
That said: is there some other way to get a specific version of Packages.txt that does not change? If so, I'd be happy to change this. The goal is that given a build, future builds should download the *exact same bits*. My understanding is
snapshot.debian.org is exactly the way to do this?