Let's leave aside, for now, the Apple fee.
1) This guy trying to argue that what he's providing is not digital content is ridiculous. Comparing what his teachers do to my renting my homes on Airbnb is silly. I wanted to understand, so I downloaded the app and spent some time perusing. Most teachers are delivering pre-recorded video and audio messages. Just like a digital song or a digital movie. Exactly zero difference. And then, we get to "live events." I see this as no different than pre-recorded. This is digital content delivered directly through the app.
2) The App charges $60/year. Is that fee shared with his teachers? I didn't see anything to suggest that.
3) Tips? This is direct income: I went to read his Linkedin post, and in the comments were many teachers supporting him. The problem was, they were all saying "this is how I make my income!" So, tips? I think Insight Timer is using the idea of "tips" to get around Apple Fees. But these are the primary way the app is set up to remunerate teachers. You don't have to buy courses. I think this is just being too clever by half.
So...imagine that you had to buy a course for $9.99. It's pre-recorded and is clearly digital content. Of course you'd pay the fee to Apple. Why not? If you owned a Yoga Studio, you are highly limited by space, and you have to pay rent, utilities, employees, etc. Here, because it's a digital product, you can reach millions of customer all at once. If only I could do the same with my Airbnb.
But this is the point, he's trying to use "tips" to get around paying the fee to Apple.
And he's most definitely delivering digital content (you know, the kind that can be duplicated to millions and millions of customers all at the same time).