As already mentioned, the comments are just that, comments that anyone can put in there, you would hope you could rely on them, but anyone can write anything in there. I would mainly go by the actual changelog, if sound is working, I can guarantee you something will be in that changelog mentioning sound working.
As far as the issues, I have mentioned this numerous times, there are many developers working on many things, sound is definitely a desire for them, but the Rhodium sound system is a beast. There are like 7 or 8 different modules that have to be written for it. Compared to a normal system that has 1. The drivers don't exist, they have to create them. It obviously isn't an easy task or it would be done. And if you have ever developed for anything, you should understand that it is a very time consuming task trying to debug and create drivers for something that doesn't exist, and then when you fail it becomes very frustrating and you need to take a break and work on other things to keep your motivation going. They are always working on things, and trying to make other things work as well. They help each other, 2 heads are better than one, and when one dev is working on something and is stumbled a lot of times they all pitch in and work together on whatever that issue was. So some things get pushed around on the burners. And during this, they find out bugs and issues and if it looks to be easy fixes they go ahead and pursue fixing those issues. It is what developing is about.
So quit worrying about it, quit complaining about it, if you want to help, help them. But constantly bitching cuz you don't have what you deem is important to you isn't working isn't helping anything. Look at what they have accomplished so far and take praise upon that. We will have things working in time. Just have to be patient, I know it is tough. But we will get there. Have faith!