There’s nothing to walk back since the post does not contest Rust’s safety guarantees at all. The link is (by design or not) effectively click bait “Linus Torvalds says that Rust is not really safe”, when in reality it is just him saying that panicky (panic on programmer error) Rust code is inappropriate for the kernel and that Rust-in-Linux code should by default limp on when it has encountered an error. That is a perfectly reasonable point to make, but has got nothing to do with “safety” in the sense that the Rust project talks about that term.