Yes, organic apple cider vinegar (ACV) is a fermented product and these are normally treated with some caution during a candida cleanse.
This is often not necessary in the case of ACV. as for many, the biochemical benefits of organic cider vinegar can be greater than any risks posed to a sensitive person by eating a fermented food.
Fermented foods are healthy foods when traditionally and properly prepared. The issue is that some folks with imbalances in intestinal ecology, react poorly to anything resembling candida or its byproducts.
Though the bacterial or fungal profiles of most fermented foods are different, if you do have a negative reaction of any kind to vinegar or fermented foods, and you want to eat other fermented foods, be mindful of what foods make you feel best and take care if you have any serious reactions.