I am not an attorney and any comments I post are not intended, nor should they be construed, as legal advice. If you need legal advice, please consult a legal expert who is familiar with the area of legal expertise you need.
This is becoming standard practice these days – https://screenrant.com/hellraiser-movie-rights-lawsuit-clive-barker/. That’s true not only with movies, but with people who are hired to do games. I remember Steve Jackson tried to buy the copyright for The Fantasy Trip from the current copyright holder a long time ago. They wanted a lot more money than the game was worth. He used this provision – https://en.wikipedia.org/wiki/The_Fantasy_Trip#Jackson_reclaims_TFT to regain control of the copyright.
In the case of Clive Barker, he can’t use stuff from any later movies that he was not involved in, but if successful, he also blocks the company from offering new movie releases involving anything to do with the characters or story he created without his permission. It doesn’t block new international movie releases as those are not covered by this provision.
With this particular provision, there are specific dates that have to be followed to regain the rights. In a similar manner, there are some things that you won’t regain the rights to if you were not a party to later games or movies. In some cases, your relationship with the company may restrict your rights as well. If you are an employee as opposed to an independent contractor, then your rights may not apply. If you have a work-for-hire restriction in your contract, you are considered an employee.