Who says this is a feature?
The 7 day delay only applies to files deleted through garbage collection. Not deletions processed by the node immediately. Now I know there is an issue where not all deletes get processed fast enough by the satellites and as a result some of the normal deletes will get caught in garbage collection instead of being processed right away. But this is something that needs to be fixed. It’s not the intended way of how things should work. However, I’m pretty sure that the delete messages you do see, delete the file immediately and not after a 7 day delay.
Edit: Here is the link to the list of known issues. Look under the header Garbage collection deletes unpaid data after 7 days