No, I mean these low bus factor languages don't really die as long as the BDFL keeps working on it. Biggar keeps Dark going through thick and thin. Chiusano likewise with Unison. Even if their Unison public benefit corp runs out of money, Chiusano could probably do what Dark did and buy the IP. With my programming language I'm making sure that there is no IP and therefore nothing to own. It would probably be easy for Biggar to just wash his hand of Dark as well but it takes guts to keep going in a direction you know it right, and so I'm happy to see the project continue.
I'm glad to hear it as I'm very interested in Unison. (I've been watching them from the sidelines for ages.) For those not in the loop, it's a language where your code is stored on disk in AST form, not textually. The AST representation is smart in many ways - for example, renaming a function is an O(1) operation, regardless of how often the function is used. They also have a way to serialize Unison functions and send them over the wire to other Unison programs, which is pretty sick. Their site is here: https://www.unison-lang.org/
(I'm mostly interested in it because I think it would be an ideal language for videogame scripting & modding)