Concerning kit wines:
Given time, wine will eventually degas on its own.
What does "Eventually" really mean? "Eventually" is a very relative term.
Kit wines, even after fermentation is done, still are very different from similar wines made from fresh/frozen grapes.
Let me add to what I wrote earlier; since my kit wine, which was partially degassed right after secondary, still had gas after 16 months in an air locked carboy, I would not bank on it degassing on it's own in a REASONABLE amount of time. But true, in an absolute sense, it will eventually degas on its own.
If it's a kit wine, follow the instructions and degas it right after secondary fermentation is completed. Don't bank on it setting for many months and degassing itself.