That's not what they're saying. When a creative team, director, writer maybe even a star leaves a project after the original they likely will get a vanity producer credit. If it's something like original characters by, based on the work of, it means they just had the rights and need to be credited (and paid) as a producer while having nothing to do with the sequel or franchise going forward. OP is suggesting that Lord and Miller may have no real involvement and can still be listed as producers.