What? Zig is definitively not memory-safe, while safe Rust, is, by definition, memory-safe. Unsafe rust is not memory-safe, but you generally don't need to have a lot of it around.
Safe Rust is demonstrably not memory-safe: https://github.com/Speykious/cve-rs/tree/main
By definition yes. There were a lot of lies to persuade managers. You can write a lot into your documentation.
But by implementation and spec definitely not.
The second you have any `unsafe`, Rust is _by definition_ not memory-safe.