I forget the name of the new system, I want to say it's something like CLDS. And I'm sure I cannot explain it as well as current cadets can, as they are living it.
But the general theme was that upperclassmen became responsible for the development and performance of the lower classes. Understand, there are those who will argue about the new system. But the general idea was that hazing & super tough environment by itself did nothing to teach leadership.
So they retooled, and kept traditions that did help develop leaders. Or did not inhibit that development. And rolled in accountability for the performance of the squads, companies, etc. Much more like real life!
Seeing it in action via DS, I have to say it's impressive, and seems to have accomplished the goal of better teaching leadership.
Yuks- (Sopomores) are corporals, and are each assigned a plebe to act as mentor. They are referred to as team leaders. Their job is to help their plebe transition into academy life, coach them, and are a go-to person for questions, etc.
Cows- (Juniors) are Sargents, and lead the squads, platoons, companies, etc.
Firsties- (Seniors) are the cadet officers, and lead the cadets through the NCO's.
All have a vested interest in the performance of the lower classes. And learn leadership along the way.
If a plebe does not do well, it reflects on the team leaders, the Sargents, and even the cadet officers. And they work to help get the plebe back on track.
If a plebe has problems with the APFT, their team leader will be working with them to resolve it. Same for other problems.
There were other changes as well, but that's the quick answer. Hopefully some cadets or recent grads can comment. While details may have changed, it appears the overall current structure is very similar to that described in "Duty First" and "Absolute American". "Diary of a West Point Cadet" is another good read, written by an 2006 grad.
Hope this explanation helps!