I’m pretty sure the most recent Fox special used a different person. He wore a different mask that exposed his hair and the lower part of his face, and it didn’t look like Valentino at all. Perhaps the different “look” made it a different character, thus not covered by the copyright? I don’t recall if the show called him the “Masked Magician” this time. Maybe the copyright was licensed to the show.
After Valentino revealed himself last time, I wonder why they used a different magician for the new episode. Could it be that some part of the fun would be lost knowing the secret?
According to this page, Valentino’s identity was known very soon after he did the first episode. Is the new masked magician as obvious?