I think it's an awful change. GDKP is the best raid format outside of guild runs.
In all 3 of the classic releases (classic, TBC, WOTLK) GDKP has been the most popular raid format by far for pugs. SR and other variants were rare because they were unpopular and garbage. This change forces pugs to use those systems and they are not as fun as GDKP because they don't attract good players, organizers, or provide similar incentives. They also strip players of agency (the ability to choose how much they value and item).