If you don’t add any faces, then it wont try to identify face. Not sure what you mean by automatic videos.
The recent resurfacing of photos issue is not really surprising if you think about how photo deletion works in Photos. When you tell Photos to delete a photo, it moves it out of the main photo index and then moves it into an index of recently deleted photos. This works kind of like the trashcan for deleted files in that you can still see the photos and if you decide to undelete the photo, it can be put back in the main index. While in recently deleted index, no photo files are deleted, they are just hidden in the main part of Photos. Every day a timed process is supposed to check recently deleted index and delete files that have been there for 30 days. It then sends instructions to the operating system to delete the file and the file gets deleted.
In this case, there was a bug that sometimes wrote the wrong data to the recently deleted photos index. The photos were hidden but not available when the automated process looked for photos to delete. The files for those photos just sat there in the folders of the photos library with no links to them in the Photos index. At some point a new update was released that checked for lost photo files. When it found some, it helpfully added them into the Photos index and they were visible again. I have had photos disappear before when a storage device was getting flaky and photos might drop out of the index. Rebuilding the Photos index will restore those files. I haven’t seen that particular problem in a few years but it is possible.
Those photos were never actually deleted, they were hidden and scheduled for deletion but that last step never happened. This was not sketchy, it just points to a weakness in the index database system for Photos that should be investigated and beefed up.