This video is optimistic, but at the same time quite pessimistic...

Things I've thought about while watching:

1. Why is this coming up now and not in 2011 or 2001? It is too late for it, I doubt you'll be brave enough to deprecate the old syntax. Or have it implemented soon.
2. This is another talk where you propose adding new things to C++, but remove nothing. After that you have the bragging rights to tell us how C++XY is simpler than its predecessors. In the real world it is quite the opposite - every new version is a lot more complex to use on a day to day basis.
3. I hope you've taken DLL interfaces into account. (I know these things don't exist in the book, but the real world doesn't care about the book). It would be quite funny if a function signature changes just because one of the parameters has changed. :)
4. You size comparison is incorrect. In your example you're using all the functions, so the compiler should generate exactly the same code. I think this is badly presented or you're confused by godbolt. I don't argue that having this done by the compiler would lead to smaller binaries in real code.
5. I don't know anyone doing the const& and && variants. If I new one, I'd question his sanity. Really. Time is too short for us to do these things.
6. Building new things on bad foundations doesn't seem right to me. There are so many things in C++ which are broken at the moment and after the last 4 additions the language seems even more broken.

Sorry...

p.s. The only reason C++ is still in business is because there are no alternatives or the newer alternatives miss the point of C++.