<p>It seems to me the overarching raison d'etre for CV is to create a body of high quality information about statistics, machine learning, etc., and only secondarily to provide short term assistance to individuals (although that is clearly worthwhile as well).  Working from that principle, I see several conclusions:  </p>

<ol>
<li>If there is valuable information in the answer (even though the OP will most likely never provide the requisite additional information), then the thread should be undeleted.  </li>
<li>If allowing such threads to remain deleted will discourage people from providing high-quality content in the future, the thread should be undeleted.  </li>
<li>If neither condition is met, the thread can remain deleted.  </li>
<li>If the conditions are met, but the OP objects, I believe <s>moderators</s> <em>developers</em> have the ability to remove the connection between a post and its original author so that the post is subsequently shown as being owned / authored by the community user.  If that can be arranged, it seems like a viable compromise.  </li>
</ol>
