I can't speak about waxes, but I doubt that claying will completely remove polishers that are polymer-based (or whatever they are chemically made of). I say this because I asked Sal Zaino about claying a Z'd car - he said it would not remove the polish. He explained that the polish/sealant may get contaminated over a year or so and that claying would remove the surface contamination, not the polish.
From my own experience, I have found some polymer polishes/sealants are not as lasting or resiliant as others, but I would have to presume that if the polish is in decent shape, claying will probably not remove it.
But hey, this is just conjecture on my part....