Higher temperatures do indeed make the wort less fermentable and thus makes a sweeter end product. However, I don't think I've ever seen a mash done at 162. The highest I've personally ever gone is 158 and that was for a pumpkin ale that is meant to have tons of body and malty sweetness (and finish at an FG around 1.018.) But this beer is meant to be drier (FG around 1.008) and is already pretty weak, so doing 162 you'll probably be looking at a cloyingly sweet, 2% abv mess of a beer.
This recipe (and style, really) is meant to be light, dry, and refreshing and as such should be mashed in the low 150's.