Adding a world generation may be helpful to be compatible with older saves.

Hello, the Mojang Studios,

In 1.18, the height of the overworld will be added to 384, that is a exciting change for the players who want to create a new save in the new version,but for players who played an old save for a long time, the change may make them never update,beacuse their saves won't be able to be loaded in the version, or can be  load but in a strange way like generating a edge.

I thing a new world generation option should be added to the Minecraft.For the new saves or saves created in some 1.17 snapshots, the option may be enable by default.But for older saves, the option should be disabled by default, but can be enabled if the player want to.