Yes, there are similar ideas to removing points, like masks and other transformations. Removing points is merely a 3D equivalent of the idea of destroying potentially adversarial information. I guess you can "remove" a pixel by setting it to a certain color, so my statement is not entirely accurate. However, point-removal methods are able to take into consideration the distribution of points, which is unique to 3D point sets. Furthermore, there are a lot of redundant points on the surface of an object, which means that removing a few points will not destroy the shape information.

This paper does suggest that we can circumvent certain domain-specific knowledge when attacking. This does not mean that we won't discover methods to utilize domain-specific knowledge in the future. I would imagine extending current provably robust methods to 3D would require domain-specific knowledge to deal with the distribution of points.