I think the art gallery owner is making an unsubstantiated fuss about this, perhaps to gain some public attention.
I re-quote here the online article I posted.
Museum officials call his charges "meaningless." They say the museum has been completely open about the works' complicated history.
"We never claim that Degas touched these bronzes," said museum curator Wendy Blazier. "This exhibition is about the history of the sculptures, and our understanding of Degas" and his working methods.
To get further clarification, I went into the Museum's website. This is their announcement of the exhibition, taken from this link
Degas in Bronze: The Complete Sculptures
One of the most important artists of the 19th century, the French painter and sculptor Edgar Degas spent his entire life investing the figure in motion through countless studies of ballerinas, racehorses and bathers. Degas in Bronze offers a rare opportunity to view 74 sculptures, posthumously cast in bronze from Degas' original composite and wax models. Degas in Bronze is organized by Joseph S. Czestochowski, International Arts, Memphis, Tennessee