I think Flash himself would be really interested. After all, it's about him. He'd be curious to see how the writer of the fanfiction portrays his character, his powers, and his relationships with the other members of the Justice League.
Batman could also be very interested. He's always analyzing things and trying to understand every aspect of his teammates. Watching the Flash fanfiction would give him more insights into the Flash's character, potential weaknesses, and how others view him. He could use this knowledge for future team strategies or just to understand the Flash better on a personal level. And, he might enjoy critiquing the plot and the writing style as well.
Well, it could be about the Justice League members sitting down and reacting to the Flash's adventures in the fanfiction. Maybe they laugh at his silly mistakes or are in awe of his heroic deeds in the made - up stories.
They might be really surprised. Some of them could find it funny to see how fans imagine their adventures and relationships. For example, Superman might be amused by the creative ways fans write about his powers and his interactions with Lois Lane in the fan - made stories.
They might have a range of reactions. Superman could be amused or a bit confused by some of the wilder interpretations of Batman. Wonder Woman might find it interesting to see how fans perceive the Dark Knight's world. Flash might laugh out loud at some of the more comical fanfictions.
They might be shocked at the alternate versions of themselves and the events in the Injustice fanfiction. It could make them reflect on their own actions and relationships in their own universe.
They might be quite surprised. Some members might find the different interpretations of magic and heroic concepts interesting, while others could be critical of how the Fate world's rules are applied in the fanfiction.
They might be quite amused. The Justice League members, with their own complex backstories and powers, would see different interpretations of the Arrow universe in the fanfiction. Some might find it interesting to see how fans envision the crossovers or alternate storylines that could involve Arrow characters.
I think Batman and Robin (from Young Justice) would be really interesting. Batman's brooding and strategic mind against Robin's youthful enthusiasm.
Wonder Woman could be the most vocal as well. She represents truth and justice in a very direct way. In a fanfiction meeting, she would likely voice her concerns about any actions that might go against the values of the Justice League. She would also be quick to support any initiatives that promote peace and equality, and would make sure her voice is heard when important decisions are being made.
Batman is often a very popular character. In fanfiction, he can be portrayed in different ways, like a more nurturing mentor figure to the Young Justice team or as a master strategist leading the Justice League in complex battles.
Definitely Superman. He has the strength and the moral compass to try and understand the Hulk. He can also withstand the Hulk's attacks to a certain extent, so he could be the first to approach the Hulk and attempt to form an alliance. He might see the good in the Hulk, similar to how he sees the potential for good in Lex Luthor at times.