@DelacoursLangur I don't know and I don't think anything has been released. The first giant panda born at Pairi Daiza in 2016, Tian Bao, is also still there (in an exhibit opposite to his brother and sister) as his plans to return to China never went ahead. I seem to remember reading or hearing something about their moves depending on when they decide they need them in China, but I don't remember when or where that was. All I quickly found was Pairi Daiza making some kind of agreement with China.
@KevinB Yea, it has always irked me how China politicizes its native wildlife... They are nearly gone from the states now since relations have soured, not that they ever let zoos keep cubs long.
@DelacoursLangur As far as I understood it the need was more in terms of use for breeding programs, but politics have always been tied to pandas, unfortunately.