...I think we are going to see fully re-energised, revitalised Unai next season.
One up side of a large turnover, is the number of players new to Emery's style (meetings, intensity, etc etc) ... which may also help keep enthusiasm levels fresh for existing players as well.
My impression of Emery is that he thrives when there's a challenge to overcome. The risk was going into a new season demotivated because all his favourite players have left - but it may turn out to be the opposite... The 'challenge' is how to integrate a whole pile of very talented new players into a cohesive tactical system.