I agree that most directors, producers, singers, or actors will not read a message or letter than contains any hint of suggestion regarding their works. I wonder how many really great ideas just died in the dust because the right people just didn't care to read even a few lines of introduction.
However, please don't assume I am "looking for bucks". Money is not as motive here. Of course it would be nice if something came from it, but it's not my goal. Your assumption is understandable, but most folks who don't know me have no clue what I'm about.
I guess "peddling my idea" or "seeking knowledgeable help to present a potential story idea" depends on one's outlook. Sadly, cynics are too easy to find.
For sure, there is no way anyone can know what's inside another person's head, that they might make a statement like "Hey, that was MY idea!" I would think they'd have to prove it, but there are so many ways to pre-date and fake "proof" today.
However, I have never heard of this particular idea before, and I believe it to be original. It's a sequel to a movie I saw when I was a child (and many times since), and the idea formed years ago that this should have continued in this manner... Though the movie was in fact followed up by an increasingly dismal set of "sequels" over several decades, none even touched on the one I "imagineered".
I have some skill as an author, but this required style writing is beyond my skill. Fleshing out believable characters and their backstories is beyond me; I just don't have that kind of creativity for it. Otherwise, I would write it out as a novel.
Nor do I (or anyone I know) have money to independently produce the work as a film.