I've had a few of my ideas copied over the years. It can be the greatest form of flattery. As long as they give some sort of nod to the original creation I am Ok with it. I do welcome suggestion but only after it is too late to change anything;)
For Disney of course I understand the protectiveness of their IP. I just have seen them come down like a tonne of bricks of people that just want to be part of their success. For me personally, I prefer to just avoid getting to close to their work snd if I am forced to make something from their world do it so bad I will never be asked again.
Is your Sibling on Hive?