[Memphiz]

Its a fork - as with any fork you can backport changes - seeing how much MrMC and Kodi have diverged in the current state there is a certain difficulty in backporting stuff. The AppleTV4 port will bring a lot of changes i guess and we (more i as nobody else will volunteer) will see how we can integrate it into Kodi once the code is public. I fear that the most problematic dependency will be python (making it compatible with 64bit arm and bitcode which is needed for AppleTV4) which is not covered by MrMC ...

And the upstream / downstream thingy also applies to forks. The project where the fork forked from is always the upstream in case the fork developers want to give changes back.