SeaWorld is silent because they remain a beneficiary of these drives, if not directly, surely indirectly. The last drive-fishery animal at SeaWorld was a false killer whale that was euthanized in 2005, but they have at least one living Pacific White-sided dolphin that came from drive-fishery acquired parents. And according to Dr. Naomi Rose, "The pilot whale Argo was probably drive-caught, but the claim was that he was a stranding" -- essentially a rescued beached dolphin -- "and [the National Marine Fisheries Service] wouldn't dig deeper."
Lastly, any expansion of the captivity industry, in general, grows the business. Folks that have participated in "swim with" programs around the world are more likely to visit SeaWorld's own swim-with program, Discovery Cove. Basically, SeaWorld and Taiji are opposite ends of the same billion dollar corporate driven industry. That is, cheap animals are collected at Taiji, and become commercial assets. SeaWorld is on the display side of that industry and is, even now, working with the Georgia Aquarium to import wild caught belugas caught by Russian hunters.