@keihdra The update hasn’t made it into the main branch of the game yet. Right now it’s only in the unstable (alpha) branch. Then it will move through testing branch (beta) –> the main/master branch (mesecraft). I tested it last night and it did generate islands at the right elevation but it seems like there was a crash too involving an inventory placement. (log above this post)
As for your game and the servers, once the update is in the main branch, it will just mean that islands will now generate around 500. the ones that have been generated already will still be there where they were.