The auto close after X days forum feature causes requests for help go permanently unanswered and yields new users, such as myself, to assume the Help section is an unreliable resource.
When this happens on feature requests, it excludes new users from adding their +1 to unimplemented features and conveys a feeling that if the devs ignore a requested feature long enough, it will get auto closed and brushed into the Feature Archive.
Examples:
Proposed solution
Allow (remind) the poster to mark the request as resolved.
If it is a feature request, include in the auto close if the feature was accepted/denied. or
Don’t use forum auto close.