"Class must contain at least four members to be relevant to this pool."
So, this should be in the pool.
Well, I was thinking the same thing (which is why I added it to the pool originally). But then later I realized Murakumo and Isonami were missing after comment #1727653 and removed it (as they were also implemented the same date, 2013-04-23, when the game first launched). Typically these four potato girls show up together though (post #2669162 and the like), but those aren't included either I think.
"Class must contain at least four members to be relevant to this pool."
So, this should be in the pool.
It means the class itself must have more than four members, (So Akatsuki-class counts, but not Nagato-class for example). The pool description also clearly states that all ships of the class are needed in the image: "An image depicting all of a single class of ship, typically destroyers, as implemented at the time." Since it's missing Murakumo, Isonami and Uranami this does not qualify.