TD14SP1 Review Space: Are resolved comments ever deleted?

Hi all. In TD14SP1 Review Space, are resolved comments ever deleted by the system? We see they remain visible in the UI, but is there a point at which they are automatically removed by some cleanup routine?

We believe the answer must be no, simply from a sanity perspective, as Resolved is a state with some extra-special magic to prevent any edits.

However we need a clear technical answer, not my speculation :-) as retaining comment history is critical to the business of this customer. Thanks!