I’m French but… there isn’t a comma, is there? “Fixes” is the main noun, “bug” qualifies the noun. “Fixes of bugs” or “bugfixes” like “weekday” or “storm trooper”. Whether there is a space or not depends on lexicalization, ie whether it feels like one concept. Bugfix is a single concept but “snow patrol” is two; and modern compounds tend to be two separate words, so “bugfix” is only joined in technical environments, maybe not for the broader audience.
Joke lost in translation. He's implying those who engage in these types of nonsense release notes often add bugs instead of fixing them.