Yarn proxies requests through Facebook's servers. It doesn't have a privacy policy, but they were thoughtful enough to have a code of conduct. The Java package repo is in the In-Q-Tel portfolio, which does funding for a certain intelligence agency. Microsoft compiler used to add telemetry around main. If anything, Google is late to the party.
Mods, can we link to the linked article [0] instead of a tweet pointing to it with nothing added?