Will coral reefs appear in an existing world?

[ChillQuil]

Really excited for the new update, just wanted to ask if coral reefs are gonna spawn in my current world where I have chunks of large bodies of salt water already loaded in, or will they only appear in new chunks?

[FlareUKCS]

The new features, including reefs will generate only in new areas, and the new world gen tweaks may include chunk smoothing, as in it may look very odd as the game tries to knit the chunks together.