Well, WRT Google Calendar in particular: https://www.discalbot.com/ https://www.discalbot.com/ I understand that's one of at least several, and that if Slack i

Well, WRT Google Calendar in particular: https://www.discalbot.com/ https://www.discalbot.com/ I understand that's one of at least several, and that if Slack isn't actively making trouble, looking for alternatives is a switching cost that may itself be prohibitive -- but if Slack is becoming really troublesome, it might be easier than you think.