Moving Elm to a different domain is a huge undertaking.
There is a big difference between a proof-of-concept or some hack solution and a solid alternative that can build a good reputation.
Elm is as nice as it is because Evan resisted the temptation of just providing some hacked together solution to an immediate need. He has invested a lot of time in the design of the language and of the main APIs.
I have not seen anyone doing the design work needed for another domain. I have not seen anyone even doing the research required prior to the design work for the domain. So… I guess you could say that work for other domains has not started yet.
Without someone actually investing the needed time, such expansions will not happen.
If you haven’t already, please read the post bellow in order to better understand what has worked so far: