The cupped leaves can be caused by several factors beyond grapevine trunk diseases.
Cupping upward
Herbicide injury
Herbicide drift, especially Dicamba or similar products, can cause cupping of leaves. In this case, you may see changes in symptom severity across your vineyard. (i.e., you may see one side of the vineyard affected more than the rest.)
(photo credit: Mizuho Nita)
More examples of herbicide injury
Frost injury
Sometimes, frost injury can deform leaves. In such cases, you will most likely find mosaic or chlorotic discoloration on leaves and shoots. You may find more symptoms in the lower part of the vineyard.
(photo credit: Mizuho Nita)
More examples of frost damage.
Mites
It is not common in the field condition; however, severe mite infestation on very young leaves can cause upward leaf cupping.
(photo credit: Mizuho Nita)
Cupping downward
Grapevine Yellows
Leaves affected by grapevine yellows can be cupped downward.
Please see this page for more details (scroll down to the bottom).
(photo credit: Mizuho Nita)
Grapevine Leafroll Disease
Grapevine leafroll disease is caused by several Grapevine leafroll-associated viruses. Similar to grapevine yellows, leaves can be cupped downward. With red-colored cultivars, you will also see interveinal discoloration where the infected leaves become red prematurely while veins remain green.
(photo credit: Mizuho Nita)
Mites
Mite infestation can cause leaves to appear yellow (bronzing) and cupped downward.
(photo credit: Mizuho Nita)