Not the sole reason for the move, there were other larger contributing factors such as increasing revenue from duty free in terminal 1. Also more space was needed so that Skyteam could be located under one roof.
Obviously lack of stands for an expansion in the near future was one of the deciding factors as you said!
Not the sole reason maybe but the other two weren't larger contributing factors. Easy was having to bus one departure in the morning which isn't wanted on first wave departures as generally this wave sets the scene for later in the day and a huge emphasis is placed on this. Duty free/concessions has nothing to do with Easyjet and is the airports reasons for the move. Having Skyteam all in one place is way down the list.