I don't really have much knowledge with oxalate foods but my best guess is low. I've come to this conclusion because of this list:
HIGH OXALATE FOODS
(foods to avoid or to eat only in small amounts)
Beverages
Chocolate milk Dark beers Tea
Chocolate drink mixes Hot cocoa
Fruits
Berries of all kinds Fruit cocktail Marmalade
Rhubarb Juices from these fruits Currants
Lemon, lime, orange peels Purple grapes Tangerine
Vegetables
Beans: green, wax, dried Beets and beet greens Celery
Eggplant Green peppers Okra
Spinach Watercress Chives
Escarole Kale Parsley
Summer Squash Vegetable soup Cucumbers
Greens of all kinds Leeks Rutabagas
Swiss Chard Tomato soup
Starches
Fruit cake Soybean products Sweet potatoes
Grits Wheat germ & bran
Meat & Meat Substitutes
Baked beans in tomato sauce Peanut butter Tofu
Fats & Oils
Nuts: peanuts, almonds, pecans, cashews & walnuts Nut butters sesame seeds
Other
Carbo Chocolate Cocoa
Which does not state milk is a high oxalate food, therefore leading to the presumption that whey also isn't high in oxalate, since whey is a derivative of milk. Unless by chance it was added in after the process.