That doesn't mean the Rust project promise no one will write a library that is not safe... The title of this submission is aimed specifically at "Async Rust",

That doesn't mean the Rust project promise no one will write a library that is not safe... The title of this submission is aimed specifically at "Async Rust", ie the language. The reality is that one third-party library with 4k stars on GitHub and 0.2.4 version number has a non-memory-unsafe leak. I'd say the title is a full-on lie.