@matigo I'd say they've been cross-pollinating for a long time, in UI. Underneath it's been OS X since day 1 of iOS, so I don't make much of a distinction there.
Not sure about this constant mumbling about how "Apple has to unify the systems" though. What's there to unify? They're already the same underneath, and if they're talking about putting the macOS UI on touch-only machines… are they insane or have those people just never used a Windows tablet?