Because Joao Felix is a forward so his job is to score goals and make assists, in Milan if he succeeds in making improvements, Ibrahimović can automatically submit a bigger offer. The point is that Joao Felix must be able to win the hearts of Ibrahimović and Milanisti. This loan period is the only key so that Joao does not continue to move from one club to another.
If João Félix can find comfort with other Milan players, it will help him quickly show his potential. If he still has obstacles like in his previous team, maybe there won't be many opportunities for him in Milan.
His current age is the best age to get into the right club and have a serious career to show his best performance. Hopefully, he really fits with Milan and can show better things with his new team.