That's a bold claim. Not that I doubt you, but do you have references to Apple doing this sort of thing?

I remember a small studio/individual developer who had their iOS update stuck in review hell after they publicized an Android port.

The app had been previously featured in the app store, and had no feature changes when the review process screetcyed to a halt. I'm hoping someone on HN remembers the details, but I'll try to Google and update this comment if I find the article. In the mean time, take it wirh a pinch of salt as I may be misremembering.

Apple explicitly does this with Apple Arcade, Apple TV, has done so with podcasts and albums in its music store.

I've personally been involved in one business discussion involving folks from Apple about platform exclusivity for an app.