Morata has never been an incredible scorer in his career. In terms of this aspect he is overrated. However he can still be supportive on attacks in an effective way. But I don't know playing as the centre-forward at Milan would be good for him. Pioli uses a 4-2-3-1 formation most of the time. I think Morata shouldn't be the only player on the front to be relied upon.
He can be more effective when he has a companion beside him. I wonder if Pioli has such plans to make a change. Because I don't remember him using a formation with two strikers. But if you have Morata in your team it is better to adopt such formation just as Atletico Madrid have done.