Those languages don't have null safety, but plenty of languages do. Rust, Kotlin, Swift, Haskell, etc.
The claim is true: a type system _can_ prevent null-related issues and eliminate the need to account for them in tests. That's not the same as saying every type system does.
The claim is true: a type system _can_ prevent null-related issues and eliminate the need to account for them in tests. That's not the same as saying every type system does.