It exists for everyone running iOS 9 / 10 (at least the earlier versions of 10, never tested later versions of 10.x)
The point is that it is baked into the software, it’s not dictated by experience. Hence my original comment....just because you don’t notice it, does not mean it’s not there.
But the original contention in this thread was that the delay was purposefully baked in to inspire users to update phones, out of frustration. If users don’t notice the delay (I don’t notice it on my 7+), clearly it will not have the “intended”/devious effect... or has that contention been abandoned?