After reading the patch notes I don't think the chain is going to completely go away. I think the new optimal thing to do may be, depending entirely on how many mobs to spawn has been decreased, will be to have a "train light" with coordinated chain groups spread apart from each other farming the same mob to spawn the NM. If you have a huge group at one point stepping on each others toes nobody is going to get light which is where the bottle neck is.