As shown here. Includes granite, andesite, diorite, and limestone.

• Minecraft: 1.12
• Forge: 14.23.5.2837
• Dropt: 1.15.0
• Pyrotech: 1.0.8
• Athenaeum: 1.17.1

From the changelog:

* NOTE: Remember to refresh (delete and re-run the game) 
your `Custom` ore dict config file or add the changes manually, 
changes will only appear in the `Generated` file.

Have you tried making sure that the .core.OreDict-Custom.json is up to date with the .core.OreDict-Generated.json file?

The generated file will always contain the mod's default values and the custom file is copied from the generated file only if it doesn't already exist. That means you can edit the custom file and your changes won't be overwritten, but it also means that the mod won't update the custom file with any new default values.

Try deleting both the custom and generated and see if they both generate.

Deleting the config for the 'custom' ore dict files unfortunately failed to propagate any sort of change, so I will be doing it manually for now.