At $159, they only need to sell 15000 to reach $2mm in sales.

Unless you thought I meant units. I definitely think millions of units is possible, if Apple continues selling hundreds of millions of iPhones. But it's not just AirPods sales. Apple makes a few dollars with every lightning device that is sold. So essentially, even if those hundreds of millions of iPhone devices don't lead to sales of millions of Airpods, they will lead to sales of 10s of millions of Lightning headphones. Which means tens of millions of free dollars for Apple.

Here's the other thing though. If Apple does not expect to sell millions of Airpods, then the whole "Courage, because the future is wireless" justification falls apart, because if not even 1% of the headphones being sold are Airpods, it's likely the future is not wireless.