I'm not sure if they would canibalise anything much. The sell each year around:
1) 230m iPhones
2) 50m iPads
3) 25m Macbooks
Macbook is pretty much niche product to them comparing to Windows market share. Many would still wanna own Macbook even if iPad would support MacOS. They would sell much more iPads and bring bring more users to their ecosystem, familiarise those that used Windows before and maybe they would buy Macbook later on.
1) 230m iPhones
2) 50m iPads
3) 25m Macbooks
Macbook is pretty much niche product to them comparing to Windows market share. Many would still wanna own Macbook even if iPad would support MacOS. They would sell much more iPads and bring bring more users to their ecosystem, familiarise those that used Windows before and maybe they would buy Macbook later on.