Afaik Herb Sutter largely stopped working on Cppfront a few months ago, and was never quite supposed to be a real thing, just a personal playground (or so Sutter claims at this point, anyway).
Afaik Carbon is at this point the only attempt at a successor language that's still going?
Probably, but note that Google says they are they main customer anyway, and it is an experiment above anything else.
Anyone that can reach out to Rust, Go, Java, C#, whatever, should do that preferably.
There are also some efforts to tame existing C++ with profiles, and replacing UB with erroneous behaviour, and that's about it.