As far as I can understand, that submissions are archived, possibly after a 3-month period. I think it would be very useful to make an exception to the stickies. For example, the PG has a sticky carried over from another archived submission. This fragments the discussion section into pieces. A new sticky would have to be created every 3 months or so, in order to keep the submission editable. This by itself is not a problem. But the original submission has lost its context in the comment section, every time a new sticky is created to replace the old one.