Nope, because its gravity is pulling it together enough to compress the rocks together and make it not porous. This is the point that I was trying to make, sorry if it wasn't clear. You get to a point size-wise where eventually you stop just getting bigger, and you start getting denser. This happens when the force of gravity overcomes a force stopping things from compressing. There are many such forces, and thus many such points where "object gets bigger, then starts getting denser, then starts getting bigger again, then denser again, etc" as you add more and more mass. Again! Speculation on my part! Take it with a grain of salt! Please don't use concrete language like "is" or else I'll regret posting my thoughts and will take them down so that people don't get confused. Those aren't facts, that's a hypothesis from me.Pluto's density does not suggest that it is porous like a comet or asteroid.
Something is reforming the surface of Pluto!