Ok. Let's check that out.
There are two laws which you'll have to confront yourself with:
The first is the law which allows you to store that kind of data for your own private use. That means that you're allowed to have those sound effects and music and listen to this stuff without any risks.
The second law, and that one will take your idea down, is that it's forbidden to share this stuff with other people.
BT sync folders are quite open. Everyone knowing the link can enter it, thus the law will kick in and you can be punished for sharing this stuff with literally everyone, because people (hackers and other people) can spy on you using the BT sync folder and hack themselves into those folders too. The downside of torrent stuff is that you're always uploading this stuff when a new user enters the folder, making it much easier to find and punish you if someone out there (maybe the game developer or owner of the music) keeps an eye on the data transfered or ordered some company to do so.
That's why BT sync folders containing such data won't be legal in any case.
You can, of course, think about the risks and how high the chances are that a) the sound effects and music used by the audio game developers were used ligally even before you got them and b) they use to check the internet for illegal activities regarding this kind of stuff.
Considering a), I mentioned this because many audio game developers intend to use already prepared music which are "stolen" from other games, e.g. Crazy Party only contains music from other games, which isn't legal at all.
So, it's your choice if you want to do that or not, but it might be possible that some ambitioned audio game developer with some amount of money might be able to track you down and you might get into trouble. Don't know how many audio game developers are out there who could be willing to do something and would have enough money to do this, but anyway. You wanted to know the current state of the law.
Best Regards.
Hijacker