It is misguided to rush to relabel art from the Russian Empire or the Soviet Union as "Ukrainian".

Given the information in the article, it would be more accurate to describe that Degas painting as showing a dancer in Ukrainian dress; but if Degas gave it a title, or (as it seems) said somewhere what he thought he had depicted, we should respect that. Being French, he may not have been aware of the difference, and it is anachronistic to make it seem that he did.