School Days is mentioned under "Harem", and at first glance, I can see why it's on the list (infamous reputation for its shocking ending and "Nice Boat" meme). Only, I don't consider School Days as a harem show. It just doesn't qualify as an example of Unwanted Harem, and calling it a Deconstruction is misunderstanding the show's actual premise (A Love Triangle goes wrong).
Makoto is being seduced by/sleeping around with other girls. Okay, and...? It's a plot point that comes up late into the series and is resolved three episodes later. (Sekai sabotages Makoto's affairs by faking a pregnancy and making a scene all around classmates. The girls then cut him off.)
I suggest deleting the example. School Days is just not important enough for the list.