I agree that it is a bad idea to describe rust this way but they likely meant memory safety as used in https://www.ralfj.de/blog/2025/07/24/memory-safety.html . Meaning that shared mutable is thread unsafe, I am unsure about Java and JavaScript but I think that almost every language on the popular memory safe list fails this test.

Again the statement is probably still untrue and bad marketing, but I suspect this kind of reasoning was behind it

Of course Rust technically fails too since `unsafe` is a language feature