This would certainly be the cause of lots of GDPR violations, considering the kinds of information processed in Word and Excel. I know our condo's owners association keeps contact information of their members in Excel sheets, that's considered PII. It can also contain sensitive information like who is behind on their monthly contributions and by how much.

That's just the first thing I thought of. There must be tons of companies and organisations processing sensitive data in Word and Excel. What about doctor's offices and insurance companies handling medical information? What about banks, financial advisors, lawyers, etc.

This is why they chose to put AI into word processors and excel. So they can take the PII in a derived but reconstructable form (weights).