Because there is such a small number of Belugas held in human care in the United States the entire population is managed as one population instead of individually by each facility. Recently to promote breeding several animals switched locations. Seaworld had 3, but the two younger animals were moved and an older animal took their place. So with only two animals currently it probably doesn't give them enough animals to ensure the interaction could happen. They need to be able to rotate the interaction animals out according to how they are behaving that day, that hour. Plus, I had heard a while back that their female might be pregnant. That leaves them with only one interaction animal, who is new to their facility.