So why has the estate finally kicked loose the rights? Has there been a death? (The main reason Amazon got the Lord of the Rings rights is Christopher Tolkien's retirement earlier this year, at a truly jawdropping age.) What's the scoop?
Amazon was probably not licensed by the estate; they are using the "Lord of the Rings" trademark, which the Estate doesn't own; Middle Earth Entertainment does. (MEE is a DBA & TM of the Saul Zaentz Company. SZC/MEE owns LOTR and The Hobbit; the estate owns everything else, so, unless they struck a deal with both, don't expect it to match the HoME nor Silmarillion.)
As for rights on Dune... Brian Herbert was peripherally involved with the writing team for the LUG Dune. He's not anti-games (unlike C.Tolkien). Thing is, the Herbert estate licensed a movie. From what I can piece together, the licenses are to maximize fan surge for the movie.
I will also say that, if it really is 2d20, I'll be less than thrilled about it. I'm buying the STA PDFs not because I'll run it again, but because the setting info is excellent, and the char gen can easily be tweaked to use CortexPlus for resolution. But I've come to detest the metacurrency-driven success and lack of real risk for PCs. The challenge my players faced was in spite of the mechanics, not because of them, and that's not a good thing for a game, IMO.
I'll also note that Modiphius has two other engines they publish, and a third they distribute for; it's plausible (but unlikely) that it may not be 2d20.