Port Lympne decided to giv up keeping Asian elephants last spring, when the two younger females and the female calf were sent to Antwerp, and the older cows and the bull Luka to somewhere in Spain. The decision was made because they had repeated failures with breeding, with several stillbirths and rejected calves. The final straw was the loss of the two year old male calf 'Sittang' to the elephant virus. He was their first successful calf to be reared after about eight failed births.
Three African cows from Howletts were relocated there and joined, as you say, by the unrelated bull 'Kruger', from Knowlsey SP. Space at Howletts is limited so spitting the African herd in this way is probably beneficial for them anyway.
My only critisism of this is that they didn't take the chance to upgrade the Port Lympne accomodation, particularly the barns, before moving in new elephants.