No, it will work fine. I do it with a bourbon oaked amber and it works great. I soak 1oz toasted oak chips in 4-5oz bourbon on brew day and let it sit till the beer is kegged. I add the oak chips in a bag and dump the now nearly black bourbon in and it tastes great after a week. I let it sit the week for the oak flavors and to carbonate, if you are just adding whiskey, I'm not sure if you would need a little time for the "flavors to meld."