as long as you dont visit a Mistlands biome you'll be fine, so generally stay away from the outer parts of the world, and try to stick to the swampls/plains closer to the center when exploring. Rn the mistlands biomes are blank and just basic terrain, and they wont regenerate when the update comes out if you get close enough for them to render (unless they find a way to fix that). So you can play in your current world.

The update I would imagine should drop this or next month, any longer then i feel like there's some development issues going on.