Well, but I’ve heard that many of the Clang people from Google have switched their gears to work on Carbon, so that might be quite an issue for future Clang dev

Well, but I’ve heard that many of the Clang people from Google have switched their gears to work on Carbon, so that might be quite an issue for future Clang development (even if Carbon is in the early stages). I think the possibility is that the Google engineers will do bugfixes for up to C++17 features but will minimize work on catching up to the latest standards (since it really takes up too much engineering effort, and Google seems to be conservative in using newer C++ features anyway and have opinions that differ from the standards.)