Of course this is from 2015, and it’s possible they’ve been prototyping for years and think they can overcome the fear of a subpar device.
But as a former Surface Pro owner who now has an iPad Pro, I don’t see that happening. The iPad is immeasurably better as a tablet when you have tablet-oriented software available. And when you don’t, obviously the Surface’s compromise of “have a crappy desktop experience too” is usable if you need to have that option. But it’s not good compared to stuff designed for a tablet.
Similarly, the chunks of Windows 10 that are clearly designed for touchscreens (like the new Settings app) are not great on a desktop compared to the older and still more powerful control panel. More consistent, sure, as any ground-up redo would be, but the information density of things like the Add or Remove Programs list is awful compared to what it was before.
I don’t think Apple is going to make those compromises. They might do a more converged developer backened for Mac and iOS to make it easier to target both platforms, but they won’t shove the frontends together.