I updated a 1.13.2 note block world into 1.14 in which I had already placed some of the note blocks in a song on top of the sounds I wanted when 1.14 would be released. In this case, I had placed in Pumpkins and Emerald Blocks into segments of the song. When I updated to 1.14, however, they retained their default "piano/harp" sound from 1.13.2.

What I expected to happen was...:
I was expecting the note sounds to update when the world was converted over.

What actually happened was...:
The pre-1.14 sounds remained rather than updating to the new ones.

Steps to Reproduce:
1. Open a 1.13 world and place note blocks on top of the 6 blocks gaining new sounds in 1.14 in a chain of repeaters with a button ready to set it off.
2. Update the world into 1.14
3. Press the button to set off the chain of note block sounds and listen for the new sounds

I didn't try tuning the notes, as the song was complete and I didn't want to mess with it. I did, however, find that removing and replacing the block the note block was sitting on updated the sounds, as well as using the /fill command to change them all into something else before changing them back.