This is true to a degree. They probably do this for a few reasons but most likely to help monitor bugs and things like that in regards to future improvements and updates. Nothing malicious to worry about! They need to keep track of versioning especially so that you can be notified of updates to WordPress itself as well as themes and plugins.
Your WordPress installation syncs up every 12 hours. A few things they keep track of: wordpress version, php version, locale, whether multisite is enabled, etc.
You can get a much better understanding of what they are tracking if you check out includes/update.php in your WordPress installation as everything is outlined in that file.