Earlier quoted context omitted.
Herein lies the problem: it doesn't matter how much 'better' or 'smoother' or 'consistent' the change is - or is not, in this case. It's a gross oversight to never inform end users of the change in any way . How many iPhone users attentively watch WWDC or read each update's (often incomplete) release notes? 1%? 3%? 5% tops? Why roll out a feature when 95% of your users will need to discover it through trial and error…
While we're on the topic, those screen-masking "tutorials" you randomly get when apps push out an updated UI are annoying. I always skip past them. When I open an app, it's for a reason, and I want to start using it.
Video games do this a lot, too. I’d play more games but it’s always a one-hour commitment to get started between opening videos and tutorials.