Lmao no. They don't have employees snooping through your files on their cloud storage offerings just to find your blackhat link schemes and deindex them lol.
They deindexed your site probably because they found out your link swaps and found it in violation of their terms, or you broke some other rule. Whatever it be, be rest assured that it wasn't some Microsoft employee going through your excel spreadsheet where you document all your link swaps
All files that you store on public cloud offerings like OneDrive and GDrive are encrypted by default. Both while they are being stored on their servers and while they are being transferred back to you.
That means no one, not even their employees or their algorithms have access to this data.
Also, you are underestimating the scale these things work in. OneNote and GDrive store petabytes of user data. Finding your spreadsheet in that would be like searching for a micrometer long needle in 20 football fields sized haystacks.
And their search engines got millions of site in their index. Do you think they will use their employee time to find blackhat link schemes of random sites?