I have not seen a discussion or policy on this.  In surfing for providers, I have notice and been tempted by some great discriptions - but the reviews are very old (like over a year) and the phone has been disconnected and there may or may not be a web site.  I really think this person has retired.  Is there any policy on this or may I suggest some flag on the provider's profile which says they are flagged for deletion by xxx date unless there is some confirmation that the provider is still active.  Then delete or put in some archive after the date.