Like @jessicat and @Pad_Pors, I’m interested in such a category-wide setting that automatically deletes topics within a category. I can see that stickies should be preserved with such a function. Maybe optional, topics with many bookmarks or likes could be kept, too, although I’m not interested in that. Do I overlook other topics that should not be deleted?
I figured with auto close and Automatically delete replies after N days most of the similar code should already be there and would just have to be adapted and put into a plugin. But the pull-request is overwhelming me.
Are there or have there already been further steps in this direction? Does the team or the community have any further interest in this?