If this sounds like Facebook Messenger or WhatsApp without the text and video calling, that’s because it is.
Sure, not needing a Facebook account is a plus, but Messenger and WhatsApp can be used without a Facebook account, too.
I also question whether invites and poke notifications will persuade users to install yet another app when the core Facebook Messenger already has voice, video, and text conversations—and now supports Zoom-like meetings with up to 50 people.