Apparently we're getting 6 new textures! And apparently all of them are going to be available for cave dwellings! BUT apparently there's a limit to quantity of wall types and all of new textures will come without parapets. Parapets, which make for the best castle designs. Parapets, which are the best option for cave buildings' tops decorating (since we have no roofs there).
Would you rather not get one of these new textures, but have parapets be available for any kind of stone building, be it usual stone, slate, marble, etc.?
Here are the soon to come new textures. I'd vote for "rendered" to stay out.
Pottery and sandstone
Round stone and Rendered
Marble and Slate
Just look at these awesome parapets. They don't want us to have them: