The thing is that all wines - including meads, are far more acidic than beer and have a far higher alcohol content than beer. They tend to resist oxidation more than beer and anyway, most wine makers are adding K-meta each time they rack to inhibit oxidation. But perhaps more importantly, grain in and of itself is full of lactic bacteria and brewers have to be constantly on guard that they are not creating conditions that favor their activity at the expense of the activity of the yeast. Wine makers are dealing with different sugars, and quite different colonies of bacteria and yeast and because of the low pH and high concentrations of alcohol, spoilage seems to be far less problematic among wine makers and certainly be a far less cause of anxiety. You have to work quite hard to spoil a wine - and degassing is not part of that picture - unless of course what you call degassing is really no more than whipping air into the finished wine...