For me this is confusing and mildly irritating, as I expect the individual post to be displayed, not the target URL. Instead, to get to the individual page of the post item I have to carefully maneuver to the "discuss/comments" section in the subline.
For me, design implementation could be improved in two simple ways:
(1) include target="_blank" inside the < a > element, so that the URL link opens a new tab (super simple).
(2) On the post stream, map the Post Title to the HN URL containing the unique item_id generated by HN (e.g., https://news.ycombinator.com/item?id=s%), and within the individual post item map the URL provided by the post author to the Post Title (e.g., https://www.quantamagazine.org/why-mathematicians-re-prove-w...).
Any feedback is welcome. Thanks very much!