"Automatically show me design ideas" is a pretty visible option in Preferences (looking at my Mac here, can check Windows later, but I remember turning that off on my new laptop since I just never _use_ the suggestions and they came up when I was traveling and on slow Wi-Fi).

I also believe it can be managed by policy.

MS FTE here, I have no direct awareness of how the feature works and am not affiiliated with Office - but I'm sad that something meant to _help_ people (if this raises hackles, I don't want to see what the OP says about the accessibility checks) is used to bludgeon my colleagues publicly.