Sure but is that really enough to get buy in on a whole new language? Especially when the new language still leaves open the door for so many of the critical problems with C?

Dangling references is about the only C problem that Zig doesn't fix with language/compiler features, everything else is taken care of and mostly in a quite elegant and minimalistic way. Also Zig doesn't need to replace C to be successful, just augment it - and for that it's a already a really good choice.

I mean zig really leaves open ONE door, which is temporal memory safety.

It is likely that zig will solve this. Rust says you must solve this with the type system. I'm not convinced that is the case.

Also, it doesn’t really have a solution. There are safe ways to concurrently access the same memory region, that rust disallows without unsafe, and if you are writing a high-performance language runtime you might well need these features.

Yeah but you'll still need something to live around the high performance features and a mechanism to check temporal memory safety would be nice.