Gutting macOS like this would strike at the very core of what Apple lovers adore. Not to mention the insult to the memory of SJ and everything he stood for and poured his heart into. I could be mistaken, but I think I recall Federighi stating they would not cannibalize their lineup. This would be doing exactly that.It's just one of my theories. It would make sense to release souped-up iPad Pro as an ARM-based Mac, touch screen and all. It doesn't matter what they call it. iPad Pro, MacPad Pro - doesn't matter. It's all about the form factor and portability.
Apple have been positioning the iPad Pro as a Mac replacement for a while. They took a giant stride with iPadOS. They just need to refine iPadOS some more & greatly enhance the desktop experience and it's an ideal candidate as a replacement for macOS.
macOS development has been on a severe decline for years, so it just adds to my theory that is isn't the future OS for the Macs of the future.
I for one am a die hard macOS person (even though Catalina). It would be painfully nostalgic to see macOS abandoned in any way shape or form.