The Mac has had the ability to run iPad apps for quite a few years now, since Apple Silicon. Unfortunately it is opt-in for developers and most don't. I wonder if it will become non-optional (or at least opt-out) with the touchscreen MBP rumoured for this fall.

I think that's the unification route they are most likely to take, hopefully along with a thinner/smaller MacBook design and built-in cellular.

They've taken so many swings at the iPad Pro (both hardware and software), and it has never been as good as the MacBook.