If Microsoft is serious, this is a great chance for trickle up. Give an org that has been using Outlook Teams and they won't have any suggestions, give it to an org using Slack and the feedback will be immense. I admit to getting caught up in the Microsoft is innovating hype from recent news but would not be surprised if they finally start to really iterate and improve on their cruft going forward. Dogfooding in the GitHub org just makes a lot of sense.