I don't think this analogy quite works. If all you wanted to do was evolve the existing C++, then sure, you wouldn't need any of this to be remotely production

I don't think this analogy quite works. If all you wanted to do was evolve the existing C++, then sure, you wouldn't need any of this to be remotely production ready. But to me, part/most of what makes this interesting is the possibility for backwards-incompatible, radical simplifications to the C++ syntax and/or feature set. Those really are only meaningful if they get to a production ready state. And by being backwards-incompatible, they inherently cannot just be bolted onto the existing C++ language spec (as if we wanted to anyway---the spec is far to complex as it is). I will say that it's impressive how much of this has already made it into C++ language specs. But given that Sutter has chosen to release this now, I get the sense that of what remains, large portions cannot continue to simply be done that way.