This is in addition to last year's announcement that "macOS High Sierra is the last version of macOS to run 32bit apps without compromise"
I wonder if we will soon see a new lineage of Macbooks fitted with Apple-specific arm64 chips.
The most scary thought is if UIKit-on-macOS starts requiring Developer ID entitlements and need to be installed via the app store, with fairplay DRM encryption of binaries and everything.
Edit: Also, r.i.p. my old macbook air 2011 :-/