Spotify doesn’t even let you buy Premium in the App on iOS anymore, it’s the same price for everyone. So no, it isn’t increasing prices since Spotify isn’t giving a 30% cut to Apple in the first place. As a consumer there’s literally no way for me to funnel money to Apple via Spotify. Spotify could choose to charge 30% more for an App Store IAP, but they’d rather be hostile to consumers and just offer nothing through that mechanism.