One idea could be that Terry's identity is revealed to the public. This would lead to chaos as his enemies target his family and friends directly. His mother might be in danger, and he'd have to constantly protect her while still trying to fight crime. It could also make his relationship with Dana more complicated, as she now has to deal with the fact that her boyfriend is Batman.
If Terry's identity is revealed, he'd probably have to go into hiding. His life as a normal high school student would be over. He'd need to find a new place to stay and a new way to operate as Batman. Maybe he'd get help from some of the other heroes in the DC universe who are sympathetic to his situation.
One interesting idea could be the reaction of Gotham's citizens. They might be shocked to learn that the wealthy Bruce Wayne is Batman. Some might feel betrayed, while others could see it as a sign of hope that someone so privileged is using his resources to fight crime.
Obviously, Batman/Bruce Wayne himself. His butler Alfred would also be heavily involved as he has always been there to support Bruce. Alfred would likely be trying to protect Bruce and keep his remaining secrets safe.
One possible plotline could be the chaos that ensues in Gotham when Batman's secret identity is revealed. His enemies might target his loved ones directly. For example, the Joker could go after Bruce Wayne's family and friends in a more brazen way than before.
In some fanfic, he could choose to face the situation head - on. He would use his intelligence and skills to counter any threats that come his way due to the identity reveal. He might try to turn public opinion in his favor by showing that his actions as Batman were always for the good of Gotham, despite operating in secrecy.
In fanfic, his identity reveal could also lead to a public outcry. Gotham's citizens might have mixed reactions. Some could see him as a hero who has been secretly protecting them, but others might fear his power and the fact that he has been operating outside the law. There could be calls for his arrest or for more government control over vigilantes.
A really cool 'Batman Beyond' fanfiction is 'Future of Gotham'. This one takes a look at the future of Gotham City itself, with Terry as Batman facing threats that could change the city forever. It has a unique take on the technology in the 'Batman Beyond' universe.
Sure was. Batman Beyond was indeed a comic that explored the adventures of a new Batman in a dystopian future. It had unique storylines and art styles that attracted many fans.