Does this wear pattern on my shorts indicate an issue with my position on my road bike?
It looks like your saddle is positioned quite far back, relative to the post.

Swapping the seatpost for one with more layback (offset) should allow you to keep the same saddle position relative to the bike but clamping the rails further back, where the saddle is wider.

Clamping further back on the rails may also reduce the risk of bending the rails.