Easyhoon is a better azir than faker and suits control mages compared to faker so I guess that's why they did it. Meta suits Easyhoon.
They let easyhoon start against GE Tigers in the final in Korea and won 3-0. But since in this series they need to win the next two games, there is no one better to sub in than faker to clutch. SKT are so good at coming back in best of 5s.