There seems to be a working Haxe port of this engine, but they seem to have ditched the original website, and they haven’t committed anything on GitHub since January. I can’t find any trace of a community for this engine.
Is this still a suitable engine for 3D work? If not, what is?
I have a soft spot for Away3D because I’m familiar with the API. I have not tested it with Haxe 4. It is mature and a good tool. Anyone who was motivated to kickstart the community again and make a few commits might attract the community you desire, because any community you find around a Haxe 3D library is going to be fairly small. That said, the libraries mentioned by Juraj definitely have more popularity these days.