Devs don't do random **** like making a useless smash more useless.
Before the patch, Ike comboed better with rage. This slight KB increase, like from a slight 1 percent damage increase, makes these combos start from 0. N-Air sets up into up-air/f-air 50/50s on it's own, kinda like U-Throw, and gives a 3rd option that will catch people trying to jump out of u-air/f-air combos. N-Air also sets up d-tilt on fast fallers at 0, leading to a solid 32 damage conversion off N-Air -> D-Tilt -> B-Air, and for anyone who doesn't try to air dodge out of it, 31 damage off N-Air -> D-Tilt -> F-Air, though that isn't a true combo. Mind-games leads to longer strings
N-Air -> D-Tilt -> (Air dodge wait mind game) N-Air on landing lag -> F-Air which does 40 damage.
F-Air is more important now, as it's almost as strong as B-Air, it being fresh is more important, leaving us to use B-Air more effectively in neutral as in a lot of light heavy MUs, Ike has a kill confirm at around ~80 or so off up-throw.
F-Air is only a 1 percent damage less in terms of KB as B-Air, as the moves have the same BKB, KBG and KB angle. Back Air hits like a truck, now F-Air does too.