What Would Trudeau Do?
Is it possible that Amazon didn’t get the Silmarillion, but they did get Unfinished Tales? It’s not part of the History of Middle-Earth series, and has a lot of Second Age detail.
At this point, for example, the name Khamul the Easterling and the term "Maiar" are out in the wild, for example.
You could probably create something that looks awful like the Aldarion and Earendis story without quite tripping over whatever legal hurdles are involved.
Beyond all that?
I'd say GoT will be a huge influence - just not the wolfy-incesty-sexpositiony bit. (Just as Fellowship seems to have been an influence on the GoT TV series)
I'd say it will not look much like the Hobbit movie. (So not "Warhammer, the TV show").
But we may well see a "family" saga of a bunch of elves, Maiar and elder Dunedain as the power of Numenor encounters the "dark age" of middle earth. The characters will be flawed and complicated and all sides will have some sort of justification. When the Edain fuck up, they fuck up epically, after all and the "faithful" may well just be the least-worst.
Movie-Aragorn seems to be driven by a terror of becoming Isildur Mk2. Maybe it could be broaden it a bit - being of the Edain is pretty much carrying around a wheelbarrow of nasty fate at all times.
You can do things with this, I think.