I'm excited to see Proton expanding their functionality, but it still seems that it has some growing to do if its going to be useful in a business setting. I'm hoping that we might see the addition of a Slack App for Proton Calendar. So we can schedule events from Slack, share our availability from Slack, sync calendar to your Slack status, and keeping us appraised of changes to event from Slack

I think this might require proton calendar to enable an OAuth2 Flow.