<p>I have finally managed to find some relevant meta.SE threads.</p>
<ul>
<li><a href="https://meta.stackexchange.com/questions/177245">Shouldn&#39;t the closed-as-duplicate banner update when the title of the target changes?</a></li>
</ul>
<blockquote>
<p>Before February 6, 2013, closing a question as a duplicate caused the duplicate text header to be inserted into the question text. It was static and forever, though it can be manually updated.</p>
<p>On February 6, 2013, this process changed and the duplicates are no longer stored as text in the question itself [...]</p>
</blockquote>
<ul>
<li><p><a href="https://meta.stackexchange.com/questions/181915">Two kinds of Duplicate closing are too confusing - suggestion for a possible fix</a></p>
</li>
<li><p><a href="https://meta.stackexchange.com/questions/247142">Replace auto-inserted markdown duplicate banners with real duplicate banners</a></p>
</li>
</ul>
<p>Apparently few people think it's worth implementing: these suggestions remain un-implemented and poorly upvoted. Pity.</p>
