The law trials have been accepted -
[LAWS]15. When both sides are square, stable and stationary, the scrum-half throws in the ball:
a. From the chosen side.
b. From outside the tunnel.
c. Without delay.
d. With a single forward movement.
e. At a quick speed.
f. Straight. The scrum-half may align their shoulder on the middle line of the scrum, thereby standing a shoulder-width closer to their side of the scrum
g. So that it first touches the ground inside the tunnel.[/LAWS]
So the law has not changed, the scrum-half must throw the ball in, but the referee no longer signals it, it's the SH's responsibility.
Is OP's question whether it has to be the player playing at number 9 who does that? Can a winger step up and offer to feed the ball?
The law book doesn't specify, as far as I see - laws are described by positions, so the hooker refers to the player in between the props, even if the #2 has swapped with another (front-row-qualified) player for the scrum. You sometimes see flankers and locks changing positions at scrum time, but the player in the lock position is the one bound on to, not the one under number 4 or 5 on the team sheet.
So it's not that the scrum-half has to feed the ball into the scrum, it's that the person feeding the ball into the scrum is the scrum-half. That's how I read it.