has he mentioned he was with IB?
He did not, but that isn't even relevant.
GTC orders are never canceled at the end of the end of every day, with possibly a few exceptions like IB has.
Quote from CME website:
"Traders can also place orders that are valid until cancelled by the trader. These orders are typically called Good Till Cancel (GTC) orders and will remain active until the trader cancels the order or the order is filled."