Or maybe their reserve has dried up and they are waiting for hot wallet to be filled with enough so that they can process the payments? In any case, this does not look or sound good.
RIP freebitco.in
That's typically how the casinos when there are pending payments, mostly the hot wallets are dried up and you're right that they have just filled it so the pending withdrawals have been filled and processed.
Which, this should be checked at most times and this isn't the first time we've seen it happen to a customer when they've got pending withdrawals and didn't push through ATM.
Now my point is that they should use it if they have a few thousand BTC stashed in their cold wallet and ensure that users withdraw at the right time.
You're right, that's what reserves on cold wallets should be used for.