Yes! You can create your own tiled landscapes with World Composition without importing a tiled landscape. All you need to do is create a landscape level with the tile size you want, right click the landscape level in the World Composition window, select “Add Adjacent Landscape Level” and choose which direction you want to add to.
Here’s a livestream Epic did showing it off with a timestamp at the part where they talk about it. https://youtu.be/FrcNClb6KUI?t=2860