You could check the author's official website or social media accounts. Sometimes authors announce updates there first. Also, some dedicated novel forums or communities might have the information you need. It's worth doing a search on those.
It could imply that in the context of the novel, characters who pretend to be heroes or are false in their heroic deeds are not tolerated or have no role to play. The story might be about a world that values authenticity in heroism.
One way is by having characters who initially seem like heroes but are later revealed as false. Their downfall can be a major plot point, showing that the world of the novel doesn't accept them.
In a false hero novel, the false hero may initially be presented as a paragon of virtue. However, as the story unfolds, it becomes clear that they are using false pretenses to gain power or influence. They might manipulate others, lie, or engage in unethical behavior. This type of character contrasts with a true hero, who is guided by moral principles and selflessness.