After several claims by folks that there is a ‘hidden’ opt-out option for Microsoft Office to scrape your data for use in it’s AI training, Microsoft has come out and cleared the air. It is NOT used for AI training, but for features that require an internet connection like co-authoring a document. I have to agree with the first reply on the @Microsoft365 Twitter post.
I am sure a more official news post from Microsoft will bring more details in the near future rather than a single Twitter post.