If I bothered asking you whether X would be accepted onto your platform, and you said yes, I would find it pretty amateuristic to then come back (once an integration has been made) and ask "why exactly should we let you onto our platform"?

Yes, you're always at the mercy of the platform holder and in the end they can do with it whatever they want, and maybe I'm old school on this, but giving your word on something still means something to me.

If someone tells me they will do X (in business) and they don't end up honoring said deal due to unreasonable behavior then I will refuse to do business with them in the future. And I will let people know who ask me about it.

Maybe it's something cultural since I'm not American, but I've noticed US companies to often act like this in various situations. Many, frankly, do not care about relationships.

I find this whole thing as appaling as the recent interaction that I've had with a company where we integrated their complete free API, and once the app we integrated it in started getting proper traction, they wanted us to pay for it ("collaborate more closely"). In this example they clearly advertise it as a free API but will threaten to shut access off if you don't pay.

Obviously we're promptly removing everything from our app + they're losing DAUs (which are also important to them) because of it.