In most cases, I understand why they never say anything about male fanservice, because showing off stomach and chest isn't considered as sexualized as when a female does it, or worse. That Final fantasy Mobius thing that Russian-Chiropractic posted a long while ago is typically how far it has to go before they start complaining, and even then it mostly comes from male fans who feel uncomfortable or demasculinized playing a male character who shows that much skin, even though they have no qualms and find it acceptable playing as shirtless males to begin with.
nobody was actually complaining about Gunvolt's belly. it was an internal decision they decided to go with because they thought such a feminine attribute would repel certain types of western customers and that is technically correct. however, in reality if you're playing that "anime as fuck game" you would most likely be used to or even enjoy the anime stereotypes including the designs of the characters.