This is not an absolute. There will always be bugs, but given adequate tests and coverage, 99% of reported bugs will be a discovered but unimplemented features. This is a core tenet of Document Driven Development.
As always, the concept can be clarified with an example. While working on this page in uSDLC I note that once a section is saved the highlight is lost. I have to click on the recently saved section so I can then add a new section below it. As a responsible project member I should not let this pass. Depending on project policy and my knowledge of the document I can document my discover and thoughts for improvement either in the inbox or in the correct place in the document. The document, like the code, can always be refactored as needed. The uSDLC tasks system will ensure that this section is reviewed, actioned and implemented.