Would a cookbook or recipe author add ingredients to a recipe to be clever rather than taste? Absolutely some would. Also, they might to make the recipe different and unique, claim it as their own rather than a copied, traditional recipe.
That said, I would doubt that is the case in your stock recommendation, rather it is more in line with @Fabby's suggestion looking for specific reactions from the alcohol. In the case of wine or stronger flavored spirits are called for, the intent usually is to retain those flavors, and potentially also have the chemical reactions which might bring out other flavors. With Vodka, it is a relatively neutral base flavor other than alcohol, so to goal would normally be just the reaction flavors, not to get the flavor of the spirits coming through. Most vodka sauce recipes I have used call for cooking long enough, and diluting enough that the alcohol in the final product would be very low by serving.
For many, any intentional use of alcohol is not acceptable, and for those, flavored spirits have a number of known substitutes such as apple juice for apple cider, almond extract for amaretto, etc. As Vodka itself is usually not intended to be tasted, I do not know of a substitute for it. So, if a person wants to exclude added alcohol in their cooking, vodka sauces and stocks are likely off the table, You certainly can make fine sauces and stocks without them, they simply will not duplicate that given dish.
If interested, USDA chart is a USDA, State of NY chart of tested alcohol cook off rates so you could estimate how much alcohol would remain depending on how much you initially added and how long you continued to cook it. Also included is a chart of non-alcoholic substitutes for many common spirits. Again, given its more neutral flavor, vodka is omitted in that table.