The EFA revealed its move against the Gambian official on Tuesday, two days before the Cameroon clash, but did not provide any reasons for its complaint.
Gassama, who is one of Africa's most decorated referees, was in charge of Egypt's opening 1-0 loss to Nigeria in the group stage.
The match was largely free of controversial incidents, apart from a penalty appeal by Egypt that was waved away by Gassama when substitute Ahmed Zizo fell under a slight challenge in the area in the second half.
Asked during a Wednesday news conference whether Egypt's complaint could distract his team, Queiroz said: "Really? I didn't know about it. I'm learning it from you now."
Local reports said CAF had dismissed Egypt's complaint.
The Pharaohs will lock horns with hosts Cameroon in a re-match of the 2017 final, which the Indomitable Lions won 2-1 after coming from a goal down.
"Words like fear have been erased from our football dictionary. In our football dictionary, there is the word respect," Queiroz said of the mouthwatering clash.
"We have great respect for the Cameroon national team and its players, because they perform well and score goals, but we are ready, and after five matches I think everything is open to all teams."
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