Normally the goal with Point Clouds is how do you create a mesh?
My challenge is the opposite. Given a mesh, what is the best option for creating a point cloud that retains the color attributes of the mesh material, with the goal of exporting the Point Cloud in one of the many popular Point Cloud formats (.ply, .fits, .xyz, .pts, .csv)?

It sounds like you need to use the Attribute from Map sop to get one of the material maps into an attribute, then just delete the prims and keep the points. You can use the Add or Delete sops for that.