Yes, Trackbacks or Pingbacks could have been extended to include a similar pull-parse behaviour as webmentions are doing right now.<p>In fact I was reminded that originally webmentions were on top of pingbacks: <a href="http:&#x2F;&#x2F;tantek.com&#x2F;2013&#x2F;113&#x2F;b1&#x2F;first-federated-indieweb-comment-thread" rel="nofollow">http:&#x2F;&#x2F;tantek.com&#x2F;2013&#x2F;113&#x2F;b1&#x2F;first-federated-indieweb-comme...</a><p>As far as I understand that change is mostly for simplification, which always a good thing.