Cosmi believes Milan fans ought to be thanking President Silvio Berlusconi for this move.
"It's good for Milan that Ibrahimovic has gone," he told Sportmediaset. "Now Milan have a great opportunity to rebuild.
"We must bring Italian football to a good level and then some might want to come back with cap in hand only to find the door closed.
"If we rebuild with young homegrown players, then there will be a queue of stars wanting to return to Serie A.
"Anyone who leaves does so only for money. France and China certainly aren't the future."