Exactly. They are well aware of the fact that Android users are left out in the cold. They are only able to do this because of their market position. If they really cared all they would have to do is create an iMessage API and the community would build it for them, but they would rather try and drive iPhone sales by building a walled garden.
I mean, wink wink, it's exactly what they wanted to do. Apple wanted a closed garden, they built it, and they won't allow anybody in from outside, and for now it's working, so, for them, there's no problem.
Steve (Jobs) famously, and impulsively claimed they were going to release FT as open source - so impulsive that he never even checked with their lawyers first, because it never happened due to legal/licensing issues, not because they didn't want to.
Do you think that's true, sounds exactly like a publicity stunt to ensure a big launch in the face of having no answer to "is it interoperable".
If you say "yeah sure it is, we're even releasing it as open source" then you prevent the product falling at the first hurdle because people want an interoperable solution. Once you have adoption network effect carries you through.
Sounds like most probably a standard corporate lie by Jobs; do you have evidence to the contrary?
We had XMPP among others, and Apple decided not to be open. We now also have Signal or Telegram, which are multi-platform.