Shame on them. Very bad for them to just sneak it in, and hope we don't notice it.
When credit cards do the same thing (like changing the redemptions from HK$12 : 1 Asia Mile to HK$15 : 1 Asia Mile), at least they send us something in the mail (albeit on a small slip of paper with super tiny size 6 font).
Perhaps this is a way for them to earn extra revenue, while decreasing workload of their call center staff.
I'll raise this at the DM luncheon on Wednesday. At least they should waive this fee for DM/GO.