You might think that, if you live in a small world.
I want memory safety, but I am otherwise not a big fan of Rust. Rust tries to be too high-level like C++, making it opaque where allocations are happening. For a low-level systems language, with embedded proofs, I quite like ATS, but Vale is also promising and more like Zig.
The way zig is designed, I think it will be fairly easy to embed Ada's Spark like proof system in it.
Why do you think that?
Where did he/she even mention Rust?
Well, you do not see people mentioning Ada/SPARK whenever memory safety is the topic of discussion, do you? They mention Rust! Well, I do mention Ada/SPARK as much as I can because it is still a much safer language in general than Rust.