From https://meta.stackexchange.com/a/92006/133693


> Just to formally document the exact policies we have in place to
> remove old abandoned / dead questions, [the Community user][1] will
> delete questions in the following circumstances:
> 
> **If the question is more than `30` days old, and ...**
> 
> - has −1 or lower score
> - has no answers
> - is not locked
> 
> **...or...**
> 
> - it was closed and migrated to a different site
> 
> ... it will be automatically deleted.
> 
> **If the question is more than `365` days old, and ...**
> 
> - has a score of 0 *or* a score of 1 with a deleted owner
> - has no answers
> - is not locked
> - has a viewcount <= the age of the question in days times 1.5
> - has 1 or 0 comments
> 
> ... it will be automatically deleted.
> 
> These checks are run every week across all sites.


 [1]: https://meta.stackexchange.com/questions/19738/who-is-the-community-user