Pluto.

Always seemed very strange to me.

Until relatively recently, Pluto was thought to be at least the size of Mercury and possibly as large as Earth. If that were the case, then it would be pretty much impossible to claim it was "not a planet." But with the realization that what was being observed was Pluto and Charon, kind of smeared together, and now the realization of a couple of additional moonlets to the system, the size of the primary had to be reduced to something smaller than the Earth's Moon.

If the article is to be taken at face value, then the proposition is that all the larger KBOs, including Pluto, be deemed to be "planets," as opposed to... "KBOs". Smaller objects, I guess, would be classified on a case by case basis, the specific criterion being: are they "round?" (And, one assumes, do they orbit the Sun or some other object?) Why would anyone want to dispute this rather generous definition of a planet? Is it because it interferes with the classical solar system models (which were based on limited observations anyway)? Or what?

An analogy is the Saturn Rings. It's not a particularly good analogy but it serves. The nature of these rings was not "well understood" for some time, until it was realized that the rings could not exist unless they were composed of innumerable individual moons, satellites. Each one of the billions and billions of individual icy particles was a separate moon -- at least for the convenience of reference.

If that's so, then wouldn't it make sense to classify all discreet objects that independently orbit the sun as "planets" regardless of their location, size or compostition?

Or would that somehow interfere with planetary models?