With the arrival of Mbappe, it is certain that a new strategy will be needed in the team. In fact, Mbappe and Bellingham can play in harmony with each other, if they are placed on the field correctly, Real Madrid will have no problems scoring goals next season. But these two players need to be compatible with each other, if they cannot achieve this, there may be some confusion 
And don't be surprised that you won't see much changes even when mbappe comes because the way people are putting trust in how Mbappe will transform real Madrid and what they don't understand is that Madrid is already a made club, even if Mbappe did not come to real Madrid nothing will still change because from the beginning Madrid already have excellent players, the way it is anything mbappe is doing is doing for him self not for Madrid and it won't affect them because it was even a free agent. They did not lose anything. And and Mbappe will need to adjust to the way Madrid is playing. A lot of mysterious things will happen next season, the way some clubs will improve no one will expect it.