Agree this was obviously something that was going to happen. My prediction was 2019 tough. My thoughts was that they probably wanted to get more developers over to using bitcode first as well as ARM being almost at desired performance but not quite there yet.
In 2020 I doubt anyone will see any problems with ARM performance on a desktop or laptop.
I remember Chris Lattner giving some details to bitcode a while ago and according to him it's not possible to recompile an app for a different architecture having only the so called bitcode.
In 2020 I doubt anyone will see any problems with ARM performance on a desktop or laptop.