The reason the Safe C++ proposal wasn't mentioned is that it came years later. =] I'll see if it makes sense for us to update that section a bit, this probably isn't the only thing that we should refresh a bit to reflect the last few years of developments.
FWIW, the biggest challenge with Safe C++ is that WG21 rejected[1] that direction. And it was developed without building a governance model or way to evolve outside of WG21, and so doesn't seem to have a credible path forward.
[1]: FWIW, some members of WG21 don't agree with this characterizationp, but both the author's impression and the practical effect was to reject the direction.
To your footnote, this has been a constant refrain from WG21. One of the biggest achievements from yourself and many others was getting WG21 to explicitly reject P2137 the "Goals and priorities" paper rather than dithering and refusing to commit as happened for "Safe C++" and for the ABI paper.
I believe that getting WG21 to actually say "No" was very useful to have non-technical leadership people understand that C++ can't be the solution they need.