In my experience of Cessna 152 and 172 the POH is correct. My instructor told me never to land with a stall, and have never done so.
Some points:
On any checkout flight every instructor will tell you something different and that what any other instructor told you is likely to kill you. This is not true - every instructor is qualified to instruct, they just have different opinions, that's all. There's more than one way to fly a Cessna, despite what you read in PPRune
Do what your instructor says but read the POH cover to cover. Most instructors don't get you to do that.
It's not necessary to suddenly kill the power when you round out. Doing it gradually leads to a better landing IMO and is kinder on the engine. Leaving a bit of power on when landing and taking the power off completely after touchdown also works nicely.