Didn't neko hint at it being some sort of air dash thing?
The current sideb had a practical use to turn around mid air on the fly and be able to bair opponents, I was able to use it pretty often for gimping people off-stage. You could even use the hitbox on the charge of it to help you with that. If the new sideb actually moves him, that option will be entirely gone.
EDIT: Nvm, I remember the hienkyaku hint was directed at MK
The current sideb had a practical use to turn around mid air on the fly and be able to bair opponents, I was able to use it pretty often for gimping people off-stage. You could even use the hitbox on the charge of it to help you with that. If the new sideb actually moves him, that option will be entirely gone.
EDIT: Nvm, I remember the hienkyaku hint was directed at MK