I honestly don’t think it made a noticeable difference in terms of selling AirPods, it simply reduced cost.
I only buy phones with 3.5mm jacks on principle, and yet I stilled jumped at the chance to get Pixel Buds cheaper when I got my 5a because of how convenient they are. The decision between wired and wireless is now nearly exclusively because you prefer either fidelity or convenience over the other. Not whether or not your phone supports them. Besides, if you’re picking fidelity you probably scrutinize much more on a phone than headphone jack or not.