rujuta4me Sims 4 should definitely not be placing files directly in Documents (rather than inside the Electronic Arts folder), and it shouldn't be able to read this file either. Your white-hat hacker friend may be able to allow permissions again and then use Process Monitor, or a similar app, to see whether anything is accessing this file as you play Sims 4. I'd be interested in the results.
I don't have this file anywhere on my Mac or on my Windows PC after running the game post-update, and I haven't seen any other reports of it appearing either. So it doesn't appear to be a new feature, at least.
If you want to send me the file, or parts of it, feel free to upload it somewhere and DM me a link.