Stopped reading here: "its Master System (later called Genesis in America)".
The Genesis was the Mega Drive, not the Master System.
At the time Nintendo was not officially selling in Brazil, but there were several NES clones selling. Sega was popular, but not dominating the market entirely.
Author of the piece. This was an error added during the editing process—if you read later in the piece, the difference is sussed out a bit. The point about NES clones becoming popular in Brazil is also touched upon in the piece.
It happens again throughout the story. The figure pictured here: https://i.imgur.com/M6YHU51.png misrepresents that also as a Genesis. No Master System in Brazil was a version of Genesis. The Master System revisions included the 6 button controllers but were still Master System consoles. Only played Master System games. Not Mega Drive games.
The Genesis was the Mega Drive, not the Master System.
At the time Nintendo was not officially selling in Brazil, but there were several NES clones selling. Sega was popular, but not dominating the market entirely.