I wouldn't say "force". Meta is all in on being open these days and they're going in that direction even when they're not required to:
my view is that the more that there’s interoperability between different services and the more content can flow, the better all the services can be
[...]
it was fine to have these systems that people felt a little more locked into, but I think for the mature state of the ecosystem, I don’t think that that’s going to be where it goes
WhatsApp wasn't the first to open up but that makes sense given it has a few billion active users and an open E2EE encryption protocol is really difficult to implement.