I would be very careful with that approach. C is broken beyond repair, and C++ didn't fix it. The only sane way forward is a clean break with a cleaner syntax (or at least one that is truly context free, dammit), and fewer undefined behaviours. Much fewer.
And of course, GC and RC aren't fixes, they can't apply in the performance constrained settings C and C++ typically are used for (tiny embedded chips, video games, video encoding…).
Also there's no way I'll even look at a new language without some form of generics. They're just too damn useful. Sure we could try the Go approach and special case generics for a few core data structures, but I believe a general purpose language needs a way to add custom ones. Heck, even Go fixed its mistakes and added generics after all.
But I (mistakenly) thought we were talking about designing a language. And for this I have a point: coming up with something like C in 2023 would be unacceptable. We know better now.
Sorry about the non-sequitur.