In reply to Robert Durran:
As I recall the 2013 season was quite stormy with only the one longish weather window that the first traverse took advantage of. The north pillar ,sunny side in south hemisphere, was still icy by the time C+H climbed it. I presume their choice of N -S was dictated by conditions and timing.
This season has been very warm , with dire warnings on pataclimb about rockfall .
In these conditions SVoD may have realised that climbing up the shady sides was feasible rather than being verglassed horrors.
Edit. Still an incredible achievement.
Post edited at 11:58