It'll be opt-in until an HN headline says it's not and then there are subsequent "post mortem" articles from Google with a bunch of PR gibberish saying "whoops

It'll be opt-in until an HN headline says it's not and then there are subsequent "post mortem" articles from Google with a bunch of PR gibberish saying "whoops it was an engineering mistake", by which point everyone's become acclimated to their technological presence.