It's possible that it was a condition of the streaming license that FUNi chose to use the original soundtrack instead of the Bruce Falconer score.
I'm not sure if that's the case here because the dialogue is changed from the version I saw with the Faulconer score and it's unedited. They got rid of a lot of the cheesy one liners and the delivery by the voice actors is much better. Also Launch, in the heavily edited version that aired in the 90's, was completely edited out of DBZ. She's in this version though. It's also just titled "Dragon Ball Z" and I had read somewhere that Funimation put Kai in the title of the new dub; "Dragon Ball Z Kai". I guess it really doesn't matter, cause at the end of the day, I'm still gonna watch it. I was just curious.