As a user of google analytics, I don't know any of that.
Of course in any case Google knows and they choose how much they want to tell you.
Nevertheless, I don't feel iffy about my Interests profile participating in aggregate data available to the sites I visit. Since virtually all sites are free of charge, giving some of that insight back seems like a fair trade.
That said, having ALL that data available to Google without anonymization is a bit more worrying, although I haven't seen many examples where it hurt someone in real world.