Looking at those gifs, the writer actually does a nice job describing the major change but the two things to look at are his hands (and his trigger) and his front foot. Because he keeps his front foot in the air, he keeps his hands back which gives his bat more time in the zone with the ball. But with his old load and trigger, anderson would be late on everything if he waited until the ball was coming to put his front foot down. If you look at the first two gifs, his load starts higher, drops lower and then he brings his hands back before forward. His hands are so good that when he got his foot down fast he could get them to the zone but he was off balance, and all the power was shifted to his hands and wrists only.
With his load and trigger this year, he starts his hands higher and only drops them to his shoulder level and then instead of pulling them back, he simply finishes his bat wiggle to get his hands in position on rhythm and then hes straight to the ball. Shorter and quicker and he has the power of his lower body waiting back on off speed stuff and his hands are quick enough to turn on anything fast.
Those may look like subtle changes but they can mean everything for timing.