Thanks guys. I will request this feature. I know they want to make PD user friendly as possible but they could add an option in the preferences to opt out.
The reason I do not like it is because I usually make a few rough drafts while editing. It adds them all to the library and then places a lock on the files so if I try to delete them from File Explorer, I can't. Also, sometimes I delete the files while PD is closed and then when I open the project, I am nagged because files in the library are missing. For now, I just need to remember to clean the library after I produce.