Yeah since working from home I've seen a LOT of chatter blocked by my pihole when the VPN is off. Also browser.pipe.aria.microsoft.com, telemetry.microsoft.com, trafficmanager.net, hockeyapp.net, self.events.data.microsoft.com . And this is with uBlock origin also adding up blocked stuff constantly (so that's not even reaching pihole).

Some of them (like trafficmanager.net) do seem needed for proper operation but most aren't.

Even when I'm just working locally on a document... I really don't like this either. Nor do I like those 'helpful' O365 reports about my habits and how to spend my time.