The reason Maya skips the display of your deformer weights is because of a property that has been set on your surface object.
There is an option to work with per-patch UVs or explicit, editable UVs on NURBS surfaces. However, when you have enabled explicit UV mode on a NURBS surface, the Artisan paint tool is set to skip the display of your deformer weights - since Artisan is programmed to use a surface's implicit UVs.
To disable explicit UV mode and restore your deformer weights feedback in Artisan, perform the following steps:
1) select the affected surface
2) execute the MEL command:
nurbsUVSet -useExplicit 0 `listRelatives -shapes`;
This command disables the use of explicit UVs on all surface shape nodes associated with your selected object. Note: when you select an object in the Viewport Maya gives you a Transform node. So instead of specifying the Transform node, we apply the command to the Transform's related shape nodes.
Now Maya will display the deformer weight map on your selected surface when you modify the deformer weights with the Artisan paint tool.