I don't know when he made the repo public, but the first commit was 2021. If this were published, say, the week or so after Carbon were announced, maybe you cou

I don't know when he made the repo public, but the first commit was 2021. If this were published, say, the week or so after Carbon were announced, maybe you could argue it was a reaction to it (though still, it started before Carbon was announced, in what direction does time flow again?). But a more likely reason for it coming out now is that Sutter gave a talk at CppCon last week on this material.