AIUI, your account's contribution graph and feed are still public, not private, without a way to opt out—just like on GitHub.

I've also articulated this point, but in a negative context. This piece speaks of actor-indexed content in a positive light. I maintain that actor-indexed content is on the whole negative. It's a direct and indirect cause of the familiar social media ills and has wide-reaching privacy implications, which is bad in and of itself, but especially so when you realize that this in turn leads to a chilling effect where people simply opt not to play because it's the only remedy.

We'd do well socially to abandon the "game-changing" practice of indexing based on actor and return to topic-based indexing, which better matches the physical world.