I'm not sure I understand. The 20 miler has been part of the requirements for as long as I can remember. The recent requirement change is from
5, 3 x 10, 15, 20 (6 hikes, 70 miles)
to
4x 10, 20 (5 hikes, 60 miles)
They have reduced the total distance by 10 miles and the number of hikes by 1.