We have Slack and Workplace. Workplace is a ghost town. Maybe Workplace chat will change things but it has to do many things better than Slack. It must also have an API because so many SW companies are building integrations with Slack.
I would flat refuse to use this, or any Facebook product, at work. I don't use any of their products in my personal life and I'm not about to start using it in my professional one.
Very, very few people will have the sort of leverage you may have in this regard. Outside of tech, you regularly don’t get to choose your tools.