I would have assumed the barrier for blockbuster is something more like the iPad or iPod, which as the article notes, both Apple Watch and AirPods are. Maybe you can argue both are less revolutionary or the product categories simply in some sense "matter" less, maybe that's the point.
I am an investor in Apple but at the fraction of a fraction of a fraction of a percent level but regardless of that my lounge-chair MBA analysis would be that if they had iterative hits like AirPods they’ll be just fine. Keep trying things and they’ll continue doing great. The stock price is surprising even me