Negations are not opposites; they are the lack of something.
In some cases, we count Light and Darkness as negations, but in truth they are spectrums. Something can be light on one side and dark on the other side; we wouldn't classify that as PP, though.
PP only counts where, if it's not one thing, it has to be the other. At all times, something is either existent or nonexistent, for example.
Likewise, beauty is subjective, and something can be both beautiful and ugly depending on the person, so it's also not a logical negation.
Right now, Chaos is sounding more like NEP Type 2, which is basically PP for Existence and Nonexistence, Dream & Reality, etc.