>>8245705The movie itself is in the public domain, but personality and likeness rights are an entirely different issue. That’s why I mentioned Bela Lugosi’s estate in particular. In the US, those rights can extend up to 75 years after the actor’s death. Universal will lose the rights to Dracula way before Lugosi’s estate loses the rights to his likeness.
There are also sometimes strange loopholes in the public domain aspect. When the author of Peter Pan died, he left the rights to his books to the Great Ormond Street Hospital. Even though the works are now in public domain in different parts of the world, the British government made an exception to the law for the Hospital, giving it the right to royalties in perpetuity.
Likeness rights and royalties aren’t always clear cut, and it can get even trickier when multiple countries are involved. Personally, I can totally see a small company like Mezco not wanting to deal with this mess and just make version of the character that’s different enough to not be a legal issue.