I'd argue that is not a direct equivalent. Like @binarycat, to me throw reads "nonlocal exception", that will be caught and handled anywhere up the call stack, whereas in Rust it will always only go to the immediate surrounding try or function block, and no further.
Since we are already bikeshedding, my vote would be for error (or even just err if we are lazy in typing), since Err results is what we are constructing:
let Ok(val) = validate(expression) else {
error format!("{expression:?} is invalid!");
}
Not to mention it'd give me fuzzy, warm, nostalgic BASIC vibes 