There's no continuity with the past movies, or the Expanded Universe. If you look in the comics for example, none of the romantic partners of the Skywalker family's next generation are black. So explain what it could be if not propaganda promoting interracial marriage.
We're talking about a movie series that filmed in 75-76 in the USA, a "podunk" film that wasn't supposed to really go anywhere and the studios were hesitant to take a bet on. So it reflected the actors they could get at the time, in the culture that existed at the time. (I don't think the first interracial kiss occurred on American TV until 1969 or so.) They added a black actor to the cast for the second movie, I suspect, to help alleviate the "all white" issue since now they realized they were onto something big and realized they needed to expand.
This isn't because the universe itself was supposed to be about the whites from what I see, as if the movies had been made today for the first time they would reflect a strong cultural diversity because that is what the United States currently looks like, compared to the mid-70's. In spirit and concept (of a diverse universe), this diversification seems very much in alignment with the Star Wars vision to have interracial and even interspecies relationships. It's a series in which even robots are viewed as people.
Some of the other properties have diversified greatly over the years, including the video games, the prequels, The Clone Wars, etc. If the book series did not diversify enough, that's their problem -- and they are no longer officially considered canon, so... tough luck.
Anyway whenever Hollywood takes over a movie series they screw it up (eg LOTR vs Hobbit trilogies). They don't even care, propaganda is more important than a good movie.
I don't have an argument about LOTR and The Hobbit, I'm a fan of the books and not as much of Jackson's vision. I mourn what got lost in the translation-to-screen.
But here, what on earth do you mean by "Hollywood taking over?" Star Wars always was Hollywood. In fact Lucas pretty much defined Hollywood, with the Stars Wars and Indiana Jones properties in the 70-80's, they defined what a modern blockbuster was. And Star Wars was not a book property translated to screen; its origin WAS on the big screen and got translated to books. The comics and books are derived from the movies.
Honestly, I suspect you only label it as propaganda because it happens to clash with yours. But the spirit of Star Wars and the galactic senate seems to be all about respect and equivalency of species, let alone trivialities like gender and race. What is happening now that you don't like seems to be fulfillment of the vision that always existed but was at worst imperfectly manifest in the past due to other factors.