Google started work on Carbon due to the difficulty of getting the C++ standards committee to accept any real, fundamental changes to the language. If Google, a grandmaster at manipulating standards committees, couldn't get something passed, I don't foresee this proposal getting anywhere.
The C++ standards committee don't see memory safety or UB as a problem. If they did they wouldn't keep introducing new footguns, e.g. forgetting return_void() in a coroutine. They still think everyone should just learn the entire C++ spec and not make mistakes.
It boggles the mind that any language - let alone a systems programming language that most of the world's infrastructure is built upon - wouldn't adjust their specification to eliminate undefined behavior wherever possible. And C++'s all seem to be in the worst possible places, too.
I think once things get established the people in charge see any attempt to change it as some kind of personal insult, so they just go into defence mode. You see the same thing e.g. with Python - for literally decades they've denied that performance matters and it's really only recently that that has changed.
I think it will only get worse for C++ because the people who understand this stuff have mostly given up on C++.