I really like this concept. I think for me one of the things that kills me about Slack is the way people write tiny little stream of consciousness messages. These are way less thought through even than they would be if you were having a normal conversation and serve as a distraction when it comes to the constant notifications.

I think asking people to stop and think a little bit (which I believe recording a video does) is great. I'll take one thoughtful video over 50 incoherent messages any day of the week.

Also thinking about trying this for a daily sync/standup since we often hear that people are not really listening to their teammates during these but instead are thinking of what they're going to say instead, which is of course entirely self defeating. Taking a minute to record your own video and then being able to consume your teams videos in an non-distracted way sounds spot on.