I consider them cardio. I don't think the weight used is heavy enough to be considered strength and especially in Cardio Supersets and after burn, the weights are used to make the exercises more intense, not really to build strength.
I'd consider Afterburn and Cardio Supersets to be definitely more cardio. For me, I consider Supercuts to be more Circuit (if the weights are heavy enough) but with a more cardio effect if that makes any sense!