Last Monday around 12PM our blobs folder had ~31k folders with images. Around 3PM ~9k images were deleted, but this seems to have had very little impact on the images loading. Is there some type of cleanup job that runs and clears our unused images or something?
There is a build in job called "Remove abandoned blobs" that will remove unused blobs.
If you don't want that functionality you can remove it by going in Admin mode and find the scheduled job and turn it off :)