When did Apple say they were going to open iMessage? I do recall Steve Jobs saying this about Facetime [1] during its announcement, and that a) it was a surprise to the team building it, and b) was abandoned when Apple was sued for patent infringement by patent troll VirnetX [2], causing them to change the protocol from peer-to-peer to server-based.

[1]: https://www.reddit.com/r/apple/comments/1xuzif/what_ever_hap... [2]: https://www.engadget.com/2017/10/16/apple-faces-440-million-...