Funny. I will mention a nail in a tire to a fellow rider who never asked about a nail. Or low air pressure to someone who never asked. Or an open side or top box to someone who never mentioned losing items.
Its just me.
The subject was "strange wear marks" which most certainly is a subject that includes the feathering and the deformation of the tread blocks. While the OP never explicitly complained of squirmy feeling from the rear tire he may actually recall such a problem during conversation. He may have wanted to address it but it slipped his mind during posting.
To say any conversation should be limited to the original intent of the opening post is a restriction I dont believe is honered by anyone who has ever posted here.
And is contradictory of the term conversation.