The objectives of GIC: To preserve and enhance the international purchasing power of Singapore's reserves, by achieving a real rate of return over and above the G3 inflation rate over a long-term horizon.
http://www.gic.com.sg/aboutus_profile_mission.htm
It is therefore, preserve + taking risk (but a question of how much over and above ie how much risk - I leave this for you to decide)
GMS assumed only the "preserve" role.
Actually GMS is right. The final goal is to be "above G3 inflation rate over a long-term horizon."
I don't think this was the case. You cannot preserve without taking risk and it has been standard practice to aim to cover inflation. Anything above is looking for higher returns.