I imagine it’s a complicated situation involving lawyers, accountants etc. Hartman was kind of a big deal when he joined the cast and it wouldn’t surprise me if he (his estate) owns a certain percentage of his primary characters. It’s easy to pay what is owed on a t-shirt or coffee mug but he’s not here to negotiate something that’s difficult to put a value on like this game. Just my guess anyway. I’d happily pay cash money for his characters if that idea is ever on the table.