Also makes you wonder what it's like for a Klingon to defecate. If everything is in pairs then it stands to reason there would be two poop chutes also. Gives new meaning to the term "dropping a deuce".
So, they are reading the canon now, and they STILL can't resist the urge to mark it somehow and make part of it "their own". Redundant INTERNAL organs make sense, as we have them ourselves. Was it really necessary to go below the belt in this show? We know everyone pees and poops, even aliens have some form of that, certainly. Do we need to see it or talk about it when we have the vastness of space to explore?