Well it has to be a completed game at some point. The sounds and music had to be added. They also did a bunch of code re-writes to make it easier to develop in the future, which means faster updates. Just because they didn't add a bunch of new fucking, doesn't mean they didn't add a lot of other features. Hurr durr, there's not a lot of pussy in this update, this update sucks hurr durr
While true on the note of the game having to be completed, a completed game does not require sound/music to be considered so.
I personally like games that have little in terms of sound and music blasting you constantly, and games where I wholeheartedly enjoy the music accompanying it. Yet, music doesn't make or break the game, several other factors do. Extra pieces of story (not every event has to revolve around you dicking the other inhabitants of the manor) with great writing and interesting characters are, at least to me, far more important than ambience sounds or music in the background.
Same goes with repeatable scenes. While it's nice that this was added, I am now left wondering - why wasn't this added in earlier, where it would've taken up less time?
I'm happy for the additions that are there, but considering it took 2 months to basically add quality of life features and ambience sounds, I'm still left disappointed.