alt Hacker NewsOfficially interoperating with them is extremely onerous, to the point where their mechanism borders malicious compliance, as far as I remember.
In any case, official interoperability is only for third-party messengers communicating with WhatsApp users, not for automation or bots, as I understand, so it's not a replacement for things like this project.
Indeed, more information here: https://developers.facebook.com/m/messaging-interoperability...
It seems Meta is able to set some rules about the interoperability making it very difficult for an FOSS implementation to emerge. Additionally organizations like Signal though technically interested in this interoperability have stated they won't lower their security standards for this.