The Compose team has made no secret of the fact that Compose itself is fairly independent of Android. This week’s discovery of a nascent Compose-on-the-desktop project just underscores the point.
It will be interesting to see who comes up with other uses for Compose. That could be supporting other platforms (Web? Fuchsia? something new?). That could be supporting composition for things beyond the UI.
The biggest risk is change. We have no formal documentation or specification around Compose, nor do we have any formal API for what Compose expects from a platform. Clearly, these are early days, and so some of that might come with time. But it would be easier for a Google engineer to play with Compose for another platform than it would be for you or I to do the same. If Google wants this sort of experimentation by third parties, hopefully they will formalize how this works, so third parties know what is stable/supported and what is not.