I dare say we will see increasing selection of stock and hybriding to enhance several traits sought after in pearl bearing critters- We certainly have the know how.
In a few generations the pearl stock will be so domesticated, it would not survive without human care any better than a cow can.
Now if those Chinese would just get some of our American freshwater pearls stock, they will be able to grow many more colors of pearls including a brilliant purple, deep reds and more.
Better yet, why doesn't a very wealthy American start raising mussel stock right here? I can think of worse ways to throw away money......