This issue is still happening for me, and the option is turned OFF in the Outlook app (macOS)., also its whereabouts in no way matches the instructions for finding the option above. I am using the web version for mail, but even though I uncheck the option, it reappears when I reopen the Calendar, and is showing in the day entry. Cannot upload screenshot of the issue because the Add image button is greyed out. I HATE it when mega companies like Microsoft decide for me what I want instead of allowing me to do it, and then send me on a wild goose chase for the next hour googling for how to turn the damn thing off, and when I follow their instructions, it doesn't work. So far, staff at my uni have had three edit emails with no change after each.
Another gripe: when setting up my profile to respond here, I couldn't add my credentials without agreeing to by spammed by Microsoft, but when I clicked the Add link, it said, "you must agree to the Privacy agreement to proceed", so I clicked Privacy agreement. However there was no button to agree, meaning that they have bundled privacy with the right to spam you.