they need a subscription to Syrinscape in order to access it. I'm not sure how many people do but it will be there for those that have one. It was fun to make and use in my game so I'd share. If you want to get a taste I could add you to a game and play some of it for you.
I don't work for Syrinscape or anything, I just use it a lot and it's easy to make soundsets available for other users. They can also be used in livestreams if you do any of that type of stuff