I’d like to clarify a few points and give some more details on exactly what the new knockback behavior changes.
Previously, knockbacks generally worked as a simple impulse. This is what caused characters to fly away faster if they were moving away, or much less far at the time of the knockback if they were moving towards the knockback. In the new system, the movement pre-knockback doesn’t matter, but only in the direction of the knockback. Any movement that is not either into or away from the knockback is not affected.
What didn’t change is the ability to fight back against the knockback. Once knocked back, you still have the ability to accelerate back towards where you came from.
Rough knockback distance equivalents:
PTR: Moving into or away from knockback, or stationary
PTR: Moving into or away from knockback, or stationary, immediately accelerate into the knockback when hit
Live: Stationary, immediately accelerate into the knockback when hit
Additionally, D.Va using Boosters and Mercy in Valkyrie are currently the only “flying” modes we have, nothing has changed with regards to how Pharah or jumping heroes behave in the air.