And wine makers don't necessarily lay bottles down for aging. But if the bottles aren't going to be sold right away, like in Spain and Portugal, they generally they don't put labels or capsules on the bottles. When the bottles are ready for sale, they're labeled. That's why you see old bottles of Madeira and Port where the contents are painted or stenciled on.
As far as excluding air - you don't want ANY air exchange between the inside and outside of the bottle. The permeability of wax depends entirely on the wax. And to the people who say that the cork allows air exchange, I've always asked, and have never received and answer, as to whether or not the capsule matters. Logic would say that if the cork allows air exchange, which it shouldn't, then the capsule would matter. But good luck finding any science on that.
I always thought cork was selected as a closure of choice for its permeability to air, moreso if the bottle had to be laid down for ageing in which case nano oxidation would speed up chemical changes causing maturing within the bottle.
Does this mean the maturation changes in the bottle are amongst the components of wine inter-se with no help or requirement of oxygen or with just the O2 present in the ullage?