Workplace by Facebook to Support Multi-Company Chats, Video Calls with up to 50 people. Users can now pin messages to the top of the chat screen, set DND (Do Not Disturb) hours and reply directly to specific messages. Safety Check for Workplace, which is now mostly used internally only by a limited group of companies, all beta customers, would soon go global in January next and large organizations would be able to ask employees about their well-being whenever some natural calamity, serious accident etc happens.”]
Source: https://hackercombat.com/workplace-by-facebook-to-support-multi-company-chats-video-calls/