This is power consumption of (some of) the chips alone. That's pretty good, but the power consumption of the screen, cell radio, bluetooth, accelerometer, microphone, GPS - all of these add up to more than the power consumption by the chip. And not all of them, especially not the screen is going to be affected by TSMC's process change.

Obviously there's many caveats here based on how each person uses their device. But the broad takeaway is - a 45% reduction in power consumption by Apple's chips doesn't result in a corresponding increase in battery life. We'll only know when the final product is shipped.