In the movie, Parker wants Presley to be his client immediately because he believes Presley is a white man who "sounds Black." Alanna Nash, a veteran music journalist, told Variety that Parker was actually more excited that both Black and white kids were buying Presley's records, though she did acknowledge Parker "wouldn't have been as interested" if Presley were Black, so this is an instance in the film that's at least partially true.
Although Parker may never have explicitly said he wanted Presley because he "sounded Black," he certainly liked that he could record Black music (which he did for some of his biggest hits, like Big Mama Thornton's "Hound Dog") and see a higher return than the actual Black creators of the time did.
While there have been decades of debate surrounding whether or not Presley's utilisation of Black music and style in his success was appropriation or appreciation, the film stops short of making any moral judgement on the matter beyond acknowledging Presley was, in fact, heavily influenced and inspired by Black musicians of the time.