Swift is a different class than rust though.

Not for Apple,

> Swift was designed from the outset to be safer than C-based languages, and eliminates entire classes of unsafe code.

-- https://www.swift.org/about/

> Swift is a successor to the C, C++, and Objective-C languages

-- https://developer.apple.com/swift/

Sorry, what does swift have to do with this?

Swift is Apple's answer to replacing C derived languages, they don't need Rust.

> Swift is a successor to the C, C++, and Objective-C languages -- https://developer.apple.com/swift/

They also mention plans for kernel and firmware targets on that talk.