Never going to happen. Apple has steadfastly avoided risks of any one of their product lines cannibalizing sales from the others. Otherwise, your iPad Pro would be an MacPad Air or such already.
Apple has demonstrated their determination to control what is usable on the iPads and iPhones while also controlling the marketplace for same.
Apple has demonstrated their determination to control what is usable on the iPads and iPhones while also controlling the marketplace for same.