A Rust artifact being used as a dynamically loaded library within a Ruby process via a C ABI is one of the very first, if not maybe first ever, production uses of Rust. You've been able to do this for a long time.

That being said, it is not simple to say, take a binary Rust Cargo project and say "please dynamically link all the crates it uses" or something like that. But if you want a dynamic library to be used by something else? First-class support for that use case exists.