/playsound with the new "source" doesn't work at all in 1.9 pre 2

What I expected : /playsound with the new 1.9 arguments and the new sound names would work.

What I got instead : The command executes, but no sound is heard.

Note : This is NOT a duplicate of MC-91102. Checked that issue already, and made sure I was using the correct sound names.

How to reproduce :

1. Open Minecraft in 1.9 Prerelease 2
2. Type /playsound anysoundname player @a
3. No sound is heard, but the command executes correctly.

I looked on the wiki for the sound names and syntax, and I even auto completed the sound names with tab in the game to make sure. A couple commands I tried, for instance :

/playsound minecraft:game.player.hurt player @a
/playsound minecraft:random.break player @a
/playsound random.break player @a
/playsound random.break blocks @a

None of those work. Hopefully this wasn't a stupid mistake of my part. This is my first bug report anyways. Hopefully this helps!