"Old" type worlds do not update to newer versions

Worlds that were created with the "Old" world type that existed prior to 1.18 are stuck on version 1.17.40. When updating to 1.19 or further, they do not contain newer game elements such as Mud. A look into the code confirms they are stuck on base game version 1.17.40 and are stuck on it, no matter how much the code is changed or rewritten using external programs. Many new game elements and features are completely inaccessible due to this, including from the Creative mode inventory and the /give command.

Below is a video of me in an "Old" type world created in 1.16, testing out a new feature from 1.19. It does not work because the world is stuck in version 1.17.40.
I also included an image of the same world being opened up using an external tool, proving that the base game version is stuck on 1.17.40, while the inventory version is stuck on 1.16.221. Neither of them update when loading the world on a newer version.