Amazon has confirmed which worlds will be merging within New World servers in US-East, US-West, Australia, and Central Europe.
Community manager Luxendra advises that there will be “two separate times listed for these merges”, “one for preparation and one for execution”.
Dozens and dozens of worlds are affected – enough that I can’t list them all here – but you can check the changes for your region on the official forum.
“As a reminder, once in-game messaging is posted, players in these worlds will not be able to transfer servers,” the post explains. “They will see a banner at the bottom of their screen reminding them of this merge when they enter the game.”