I think they mostly are.
Cache is already in .cache/mozilla, so usually there is no change hence I didn't mention it. They did move the cache to the XDG_CACHE_HOME by default. And yes they are using the XDG variables including the recommended fallback values.

The line between data and config has always been blurred, Most data in the browser is "data" until a user overrides it. Even extension files presence is linked with their configured state of being installed.
For log files I'm not sure anyone follows that. Besides firefox barely has any plain logs, I think having those in the profile is fine.
Currently it's all in XDG_CONFIG_HOME