At some point this becomes No True Scotsman. They have disclosed a lot

Yawn. This has been debated ad nauseam. If you want to feel that way it's up to you, but disclosing means and hidden information has never been a requirement for open source. As long as the thing is licensed under a permissive license (MIT in this case), and you can see the data, change the data and re-publish the data, it's open source.