BC doesn’t have ED, though you can do EA and be notified 12/25.
Northeastern did just add an ED2. They do have EA, but don’t notify you until 2/1. I know a year ago they’d notify 12/15, so I’m not sure if EA has that much point there now. I don’t think it gave much admission advantage before in any case.
Emory has ED 1 and 2. The current percentage of acceptance in the two EDs combined is not much higher than RD, but they take almost half the class in ED, so it might be a significant advantage to be in one of those rounds. Certainly if Emory is someone’s first choice of the three, ED there may be the right move.