Depending on the ingredients, it should be fine. I used some peach nectar to add to a mead. I would see how far down on the list the actual cherry puree is, it just might need some more fruit to have a bigger flavor. Maybe check the gravity of the nectar and see if it's high enough. I'd probably use it for part of it, but I think adding more sugar to it to boost the gravity might take away from the fruit flavor. Not sure though.