Would not surprise if Jony has been working on the UI and it's much more advanced than we thought.
Don't think this 20% is new to Apple at all (just taken a while to come out/be speculated on).
Makes me wonder if Ive hated th software UI for a long time but had no power to do anything about it when Steve was around. If you read Adam Lashinsky's book Steve wasn't one for allowing employees to move around the company. If you were good at something that's all you did.