I hope this doesn't confuse things even further, but I see a lot of confusion over the purpose of the Redirect and Warp Shaders.
The 'redirect' in the name Redirect Shader means "redirect a displacement shader to displace along the X/Y/Z axis instead of the surface normal". Its only purpose is to change what direction a displacement shader works in, because most displacement shaders only displace along the surface normal. The Redirect Shader allows you to make sideways displacement, for example. Now, if you apply this to a surface (e.g. your terrain) and you have some other shaders, whether they are displacements or colour shaders, they will be affected by the displacement as long as those shaders work with texture coordinates, not final position. (If the shaders work with final position, they will just appear to be 'pasted' over the top of the displaced surface without bending sideways with it.)
'Redirect' is completely different from the Warp Shader. The Warp Shader allows you to use a displacement shader to distort the texture space used by another shader, which means you can warp, distort or move a particular shader without actually affecting anything else about the surface.
Redirect Shader is easily confused with the Warp Shader because, quite often, both shaders are used together to achieve a particular effect. For example, if I want to warp a texture space in 3D, the displacement that describes the warp might need to be in X, Y and Z directions. To do that I use a Redirect Shader with 3 displacement shaders attached to the X, Y and Z inputs. That Redirect Shader then becomes a 3D displacement which I plug into the warp shader to tell it how to warp the texture space of another shader. Only shaders that work with texture coordinates, not final position, will be affected by the Warp Shader.
