These days, as long as it involves a financial backer, they're bound to interfere with the filming. Sometimes they shove people in, sometimes they send someone specifically to supervise. Wang Ju is quite a renowned name, so he usually decides the main roles himself when filming, but the supporting roles are more flexible. He can't just ignore the investors, so he usually leaves some less important supporting roles open for them to fill.
But after going to Cannes this time, maybe he was hit with some kind of realization, maybe he was reflecting on his life. Although he had won quite a few awards, he always couldn't break through. If he keeps going with the flow in such a commercialized way, looking back on his body of work in a few decades with only a handful of films, it would really be quite lamentable.
