This is the sort of thing that gets filed under because he could.
There's no particular reason why Jelani Eddington would play the Star Wars theme tune on a theater pipe organ other than because he's in a position to do it. And the result sounds amazing. It's actually up there with a full orchestral rendition to my ears.
Also... wow there are a lot of pedals, keys and flippy switch things (technical term) on a pipe organ!