Nope the reserves of XMR are accurate, but indeed XMR is often empty. But it is for sure not a secret and well displayed.
Every time I visited the exchange website in the last couple of days, XMR was always at 0. But you are right. It was showing a little bit above 121 when I saw your quote. A few minutes later and it's back to 0 again. There is great demand for no-KYC monero.