An issue where the reporter is unreachable and developers do not have local reproduction should absolutely be closed as it serves no function other than generating noise in the issue tracker.
Open issues is a liability to overview and planning, and having bad open issues is therefore directly harmful to maintainers, reporters and users.
Closing a bad but ultimately real issue will just make way for a possibly good report to take it's place (i.e. a new reporter rather an old unresponsive one) so it only provides benefit.
An issue where the reporter is unreachable and developers do not have local reproduction should absolutely be closed as it serves no function other than generating noise in the issue tracker.
Open issues is a liability to overview and planning, and having bad open issues is therefore directly harmful to maintainers, reporters and users.
Closing a bad but ultimately real issue will just make way for a possibly good report to take it's place (i.e. a new reporter rather an old unresponsive one) so it only provides benefit.