To be fair (or clear, or whatever), I don't think Unity even supports Blender 2.8 yet. It's a bother because the 2.8 UI is a significant improvement over 2.79.
Maybe it's possible to author files in 2.8 as long as 2.79 is on your PATH to be used by the game engine for importing? I don't know, haven't tried that yet.
Unity shouldn't need to have to support each blender version individually. The DCC import for all supported programs works by launching the DCC program in batch mode, making it convert the file to FBX and importing that. And I would be surprised if blender broke that.
Maybe it's possible to author files in 2.8 as long as 2.79 is on your PATH to be used by the game engine for importing? I don't know, haven't tried that yet.