Who is the audience for new features in C? And who is driving stuff through the standardisation process? Is this stuff likely to make its way through to embedded toolchains? Or is this for people who are maintaining existing codebases?
You can read #13 of the Charter https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2086.htm
As for the audience, it's all the C developers, the open-source and commercial compiler implementations, vendors of libraries, tooling, services, learning material and everything else built in C; which is just innumerable.
Each Standard version released supersedes and obsoletes the previous versions. Intentionally, the versions are meant to be as backwards compatible as possible so that one can mix and match C89/C99/C11 codebases with minimum effort.
C has gained only a handful of features in the last 40 years. Compared to the great many things that are improved w.r.t. undefined/implementation-specific/unspecified behaviors, or removed to keep up with modern times (e.g. Trigraphs, Two's Complement integer representations, etc).
I'd say: (1) upgrading is not the spooky thing people make it out to be. Go, Rust, they all move much faster than this and have very ambitious big design ideas on their mind. (2) It's necessary to take good care of C as it, and the things built in it, will realistically outlive many of us.
Folks like myself who use C to write system software.
> Is this stuff likely to make its way through to embedded toolchains?
Embedded toolchains based on GCC or Clang will presumably see these features one day.
In the same way that Rust used underlying `const` attributes in LLVM (and found all the weird edge cases), and Nim used C as an intermediate as have many other lisp or object-ish languages.