I think the point of them being more vague also allowed for NSFW/questionable content games to be able to come to Itch.io in the first place. Valve/Steam has been much more transparent per se, but also stricter on adult games (until very recently). But they also have that age verification measure, which I am not sure if itch.io has properly implemented sitewide. If someone like Valve/Steam has to mass delist games to comply, itch.io would have been suicidal to act like the hero for NSFW content