It's true that Hashicorp's source is still available, but you might not have permission to use it or modify it any more. Even if you can read it legally. Under their new license, Hashicorp can essentially revoke any commercial user's license to run Hashi software, and there is nothing the business can do except pay. They can do it at any time, if the business has any divisions that to anything close to competing with any Hashi product.