They don't have to. I believe it's done for two reasons. 1). Suspense during their events 2). To keep people from buying the older devices that they are about

They don't have to. I believe it's done for two reasons. 1). Suspense during their events 2). To keep people from buying the older devices that they are about to discontinue. No reason to have to field support calls for people wanting to cancel/return their newly purchased items.