Here is my guess (or a wish). Apple provides macOS as a virtual machine in the iPadOS App Store. Download it and install it on the iPad Pro, and launch when a Magic Keyboard or an external display is connected.Why not give an option? Pair a keyboard and trackpad and the new IPP is a MacBook Air with better display.
Despite him saying this, I’m sticking to my guns and saying these new model Pros are going to be very close to being full Mac machines come WWDC.
This is similar to what Samsung is trying to do with DeX but with much more capability.
I would gladly sell my MacBook Air and buy an iPad Pro if they did this.