Probably don't, because the permissionNode can be null, and nullables should not be exposed according to the contribution guide and Skepter on Discord.
Also, does it make sense to update it in the 9.3.0 documentation since it is meant for 9.4.0? Should this even be documented?
And where would you want to add a Javadoc about this?

Probably don't, because the permissionNode can be null, and nullables should not be exposed according to the contribution guide and Skepter on Discord.

Makes sense. I suppose you could also change the method signature of getPermissionNode to be an Optional. It might be helpful in the case when you want to check if the permission is OP or NONE. Although, CommandPermission objects with a non-null permissionNode should only be these constant fields since the constructor is private. So, a developer could just check if their CommandPermission object is equal to one of these.

https://github.com/JorelAli/CommandAPI/blob/46d1fa14990f9d3b6b9611e08f4e953f886291c9/commandapi-core/src/main/java/dev/jorel/commandapi/CommandPermission.java#L44-L52

The isNegated method is probably important though for telling the difference between has permissionA and does not have permissionA

Also, does it make sense to update it in the 9.3.0 documentation since it is meant for 9.4.0? Should this even be documented?

Yeah, you wouldn't change the old docs since the method wouldn't be public in 9.3.0. You'd change the source file here: https://github.com/JorelAli/CommandAPI/blob/46d1fa14990f9d3b6b9611e08f4e953f886291c9/docssrc/src/permissions.md. Then once the 9.4.0 docs are generated from the source files the change will be visible.

But also yeah, I'm not sure if it's a big enough deal to mention?

And where would you want to add a Javadoc about this?

I meant a Javadoc on the getPermission method. Public members should probably all have Javadocs, though I'm sure there's some places where they don't :P.

Makes sense. I suppose you could also change the method signature of getPermissionNode to be an Optional. It might be helpful in the case when you want to check if the permission is OP or NONE. Although, CommandPermission objects with a non-null permissionNode should only be these constant fields since the constructor is private. So, a developer could just check if their CommandPermission object is equal to one of these.

I wouldn't change the signature of getPermissionNode because, as you mentioned, they could just check with the static instances. And for those who, for any reason, use reflection to access it, it remains accessible.

The isNegated method is probably important though for telling the difference between has permissionA and does not have permissionA

Yea, makes sense.

Yeah, you wouldn't change the old docs since the method wouldn't be public in 9.3.0. You'd change the source file here: https://github.com/JorelAli/CommandAPI/blob/46d1fa14990f9d3b6b9611e08f4e953f886291c9/docssrc/src/permissions.md. Then once the 9.4.0 docs are generated from the source files the change will be visible.

But also yeah, I'm not sure if it's a big enough deal to mention?

It doesn't really fit in the docs, so I would just not mention it there.

I meant a Javadoc on the getPermission method. Public members should probably all have Javadocs, though I'm sure there's some places where they don't :P.

Makes sense. I thought you meant we should mention the change somewhere in the Javadocs.