I was oversimplifying, sorry. You are correct that the URL isn't ever explicitly sent. However. Generally there are only one or two URLs that start with the h

I was oversimplifying, sorry. You are correct that the URL isn't ever explicitly sent. However. Generally there are only one or two URLs that start with the hash prefix that is explicitly sent to Google. Which means in practice it may as well be leaking the actual URL to Google. Especially as there are multiple hashes per URL (5 worst-case?). If Google wants to track a URL, they can do so.