Currently we only expose one port per host, and it needs to speak HTTP. I do have a use-case in mind that requires exposing arbitrary TCP/UDP ports, as long as they're specified at “spawn time”, which might not quite get at the functionality replit has if it allows you to map ports dynamically while a service is running.
So I guess the answer is “probably not in the near future, but maybe eventually” :)
Have you guys tested Drifting in Space with executing users code and opening ports? (like replit)