I don't know about the chemical reactions involved with oxygen and the components *complex !* of whisky but a photograph/chemist friend of mine confessed using Nitrogen (canned, mostly used in electronics/photography) with his old bottles
He just fill the bottle and voila. This seems logical enough as Nitrogen is mostly inert, lacks of moisturizing or oxydizing qualities !
And, as Wikipedia says, a further example of its versatility is its use as a preferred alternative to carbon dioxide to pressurize kegs of some beers, particularly thicker stouts and Scottish and English ales, due to the smaller bubbles it produces, which make the dispensed beer smoother and headier.
Let's save old bottles wit Nitrogen... or drink them !