This is work that is 5+ years old. Before casually dismissing work that is long in the making, it's worth taking a moment to evaluate it. There are some amazing talks in the README that Herb has given. I particularly enjoyed his "Thoughts on Metaclasses" talk (https://www.youtube.com/watch?v=6nsyX37nsRs) which starts with a live on-stage user study.
Herb's thoughtfulness and care for tasteful evolution is manifest in the way he describes his work, and it's a shame to see it disparaged so easily.
And yet it was released today, in a way that clearly a reaction to Carbon (which is, itself, a reaction to Rust and perhaps Swift to a lesser extent). The comparison is highly relevant.
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.
