Its not unusual as more information comes available, to adjust and modify definitions and supplemental adjectives of a word. I think you generalize the definition of planet and rely on modifiers to further categorize it. I would say a planet is a body that is large enough that gravitational forces have made round, but it is not so large that it is a brown dwarf or star (positive fusion or neutron or quark energy..). After that you could have main disc planets (for those in the main elliptical plane), eccentric planets (out of the plane), rogue planets (kicked out of original system and no longer orbiting). You also have gas giant planets, and terrestial planets to delineate other properties. For our own system, we would have 8 main disk planets, and an unknown number of Kuiper belt or eccentric planets. Of the 8 main disk we have 4 terrestial planets, and 4 gas giants. Even if you demote Pluto to a Kuiper belt planet, it can always hold onto the label of 20th century classic planet!

One area of ambiguity of the above scheme is now how do you define Moon? At what point would you have a binary planetary system versus a planet (and its large moon). I would call moons planets if they were some arbitrary percentage of the largest body (say 80%--or whatever percentage is required to consider that the bodies orbit about each other). Otherwise, I would call it a moon if it orbits the planet and has less mass (but is still round by gravity). I would call it a moonlet (if it is not round by gravity). You can still use the modifiers like main disc moon, and eccentric moonlet.

Anyway, someday we will encounter some rogue binary planetary system and with my scheme we won't have ambiguity on what to name it.