Music for acts 6-7

I'm kinda curious as to why the official digital soundtrack only includes a handful of tracks for act 6, the only references I can find anywhere to the rest of the soundtrack are highlight previews and a promise it would be included in the download when they released from over a year ago. Considering they're currently ingame, I would assume they're "finished" now?

Would be awesome to have these added to the download, the coast and plateau themes from act 6 are among my favourites right now.