I think only time will tell if this move is a good one and that's the same for Thomas Tuchel who is currently the head coach of the England team. His move to England was accepted by many and also questioned by many but we will soon see how this goes especially in their world cup performance next season which I think is among the main reason they signed them.
Ancelotti has had great success in coaching a number of clubs and it is only right that he seeks a challenge in the Brazilian national team and I am sure there will be big changes that can be made because a number of Brazilian players do have sufficient quality which will make it easier for Ancelloti to manage the team. Time will prove it to him and vice versa for Thomas Tuchel who is now the coach of the England national team and in the upcoming World Cup they can prove the quality of coaching in handling their respective teams.