Earlier quoted context omitted.
> The company doesn't need to expose custom APIs on their data. If they implement a chat protocol, they must allow other clients to interface with it. And how would that work without a way to talk to the company’s chat server, and document the way to do that, and commit to keeping that way of communicating reasonably stable? In other words, an API? Which implies sort of a commitment to the way that chat protocol work…
The comment you're replying to already answers this, so I'll refer you to that
I just doubt you really thought this through.