Even if the long term goal is more portable GPU support it still makes some sense to get a CUDA implementation up first if it is easier to get to. It then allows real world testing faster, can always go to openCL later once they know more.
Just out of curiosity: how often did you see that happen (not only related to GPU's, but technologie decisions overall)? In my (little) experience the change at a later moment will not happen. Most of the time because the management has a new idea/project which you have to attend to.
