The nodes will freely expand because a Deformable Remote Displacement scoped to the surface is an element that takes the average of all the surface nodes and creates a new point at the center. You tell it to hold this center point in all DOF at 0. The element adds no stiffness to the model.
Insert a Deformation plot into the Solution branch in Mechanical and you will see the displacement. You might want to create a spherical coordinate system so you can plot the radial component of deformation.