Yes, ShelLuser has got it right that why renaming a pool shape won’t cause the pool to remap its model element, as it has big impact because the two pools are distinct model elements before, if a remap occurs just by casual renaming, a merging of model element relationships/properties/children will occur which could be undesirable.
The name to existing pool remap does work, and only works, when you name the pool after you have just created it. It is designed to work only when create because there is no risk mentioned above.
To remap a pool’s model element, simply right-click on the pool shape and select “Remap Pool” from the popup menu, then you can select any existing pools to remap to this shape.
Note that the old pool model element won’t be deleted after remap, you have to locate it in the Model Explorer or Project Browser to delete it manually.
Hope this helps.