How it works is:
- If you only use Source View to manage your properties, they will stay as you formatted them.
- If you ever use Properties View to edit them, they will be reformatted.
- I think if you view your properties in the new UI but don’t edit them, they won’t change, because I remember reading that deprecated forms of keys will still be recognized by Properties View for reading. But I might be mistaken.
This had been discussed a lot and the team has explained their reasons (mainly in the insider-desktop channel on Discord) but I’m having a hard time finding those posts now. There’s a brief partial explanation at Properties: Do not strip hashtags in tags - #16 by WhiteNoise, and the user post right after that goes into some detail, but I know I’ve seen other posts about different aspects of it.