pitch option in sound_definitions is ignored

The bug

The sound_definitions file allows for an option for sound pitch that is used by several vanilla sounds. However, it does not work, and the original pitch from the source sound file is always used. I have confirmed this issue to exist in most places sounds can be played in-game.

How to reproduce

1. Download the attached world
2. Press the button on the left, then the right
   →  Both sound identical

The resource pack contains a single sound_definitions file with pitch specified, so they should sound different.

Note
Obviously /playsound has its own pitch option, which works fine. However, the sound definitions pitch is still ignored in all other contexts, such as mob sounds or animation sounds. Additionally, this bug makes it impossible to pitch the individual sounds that comprise a sound event when using /playsound.