Nothing to do with foreseeing the economy. It has to do with manufacturing ramp-up. Yes, Apple could have held off the announcement of AirPods until they had a huge inventory, so they could ship overnight, 3 months later, perhaps. But the wait would still be the same or longer. You just wouldn't know about it because they hadn't been announced.
If you follow the trade press you would know that Apple had quality problems initially. AirPods are the first Bluetooth headsets that are totally wireless, meaning that the two pods each receive their own content, rather than only one receiving it and syncing it with the other via wire. The problem was keeping 2 independent Bluetooth connections in sync. They eventually got it to work, but after the product was announced.