Looking at Apple’s recent history of new product launches, it seems that delays are the norm rather than the exception.
AirPods were originally promised for late October 2016, and actually went on sale in mid-December. HomePod was announced in June 2017, promised for December 2017, and wasn’t actually available until February 2018. In both cases, Apple missed the all-important holiday gift season, whoch undoubtedly hurt launch sales.
Källa: Comment: Apple’s habit of announcing early, delivering late, is worse for Apple than for us
