I think it isn't an intentional knock on because the ball doesn't touch the ground. You have to read the laws together.
DEFINITION: KNOCK-ON
A knock-on occurs when a player loses possession of the ball and it goes forward, or when a player hits the ball forward with the hand or arm, or when the ball hits the hand or arm and goes forward, and the ball touches the ground or another player before the original player can catch it.
‘Forward’ means towards the opposing team’s dead ball line.
12.1 The outcome of a knock-on or throw forward
(f)
Intentional knock or throw forward. A player must not intentionally knock the ball forward with hand or arm, nor throw forward.
When you read all three in concert (f) doesn't apply because no knock on occurred.