As the title reads, the new mobs added are not shown in the menu to pick your pet.

Those pets need to be manually added to an existing config as they will only appear in newly generated configs.

You can:

• temporarily save your existing config in a different location.
• start up your server and let a new config file form.
• copy the sections corresponding to the guardian and rabbit pets over to your old config.
• replace the new config with your old config.

Oh yeah, I saw the config updated with the new mob settings, just not the menu entries. Thanks.