Perez said that the league was formed to attract a younger audience to football and recoup income lost during the coronavirus pandemic.
However, critics said the move was driven purely by money and would destroy domestic leagues.
Bruce, who won three Premier League titles at Manchester United as a player, credited the lower divisions for giving him a start in his career, having made his professional debut in the third tier with Gillingham in 1979.
“I’m all for the pyramid in this country and I’m all for the way it works,” he said.
“Thankfully the big six have taken a slap. This thing must have been rumbling on for years, so we must guard against it.”