As for users who HAVE been affected by whatever this "thing" is -- here's what Intuit Community Guru Nic is saying:
...For those of you who have been affected, we are testing out options for recovering the deleted files. Our recommendation for now is to shut off your machine and do not use it further. If you continue using your computer, you may over-write the area on the disk where the deleted data is stored, preventing any recovery efforts from being effective.
If you have been affected and have lost files, and haven't already posted your contact information in the original discussion, please email your contact information to Quickbooks_community_team@intuit.com. We'll get your contact information to the team that is working on this, so that you can be contacted for follow-up.
Intuit has also created a Knowledge Base article about this issue. We'll keep you updated as we get more information.