I did some deep digging on this last month and technically yes, Youtube ad revenue on a UAV video counts as commercial use. Even other supposed loopholes like making drone video a 'free bonus add-on' to a purchase of non-UAV photo/video isn't exempt. The way it's determined is if money is changing hands as a direct or indirect result of the video captured by the UAV, or if the UAV footage itself is being used to compel a buyer to make a purchase, then it's "commercial".
It's pretty feeble ground that the FAA is on with the commercial use verbiage and especially their ability to patrol/enforce it - but it doesn't mean they can't and won't come after you and make you spend lots of money on attorney's fees to defend yourself. The Arkansas case from what I understand has a lot of voluntary financial pledges of support from all over to help fight it, if it does go to court. There's no guarantee that this kind of voluntary support would be there for anyone else who might find themselves in that situation.