In such a fanfiction, Harry would likely be in shock. His world view has been centered around their deaths for so long. He could be hesitant to trust this new reality. But once he does, he'd have a whole new support system. His parents could teach him magic they've learned in their 'hidden' years. This would make him even more powerful and give him a different standing among his peers.
His confidence would probably soar. Knowing he has his parents, who are likely strong ninjas, supporting him would make him feel more secure. He might become a bit less reckless as he now has people who care about him deeply and he wouldn't want to worry them.
Naruto would probably want to introduce his parents to all his friends. It would be a big moment for him to show off his family, especially to Sasuke. His relationship with Sasuke could also be affected in a positive way as Naruto now has a more complete family.
Well, one thing that could happen is that Naruto would be overjoyed. He has always longed for a family, and to suddenly find out his parents are alive would be a dream come true. He'd probably have a million questions for them about his past, why they had to be away, and what their lives were like. And his relationship with his friends might change a bit too, as he now has this new family aspect to his life.
A potential plot development might be that Voldemort, upon hearing that the Potters are alive, would be enraged and try to attack them again. This would lead to a new series of battles and challenges for Harry and his parents. They would have to work together to fight off Voldemort and his followers. Also, Harry's parents could help him unlock new magical abilities or knowledge that he didn't have access to before because they are more experienced wizards.
Well, it could be about Harry Potter finding a will left by his parents. Maybe in this fanfiction, the will contains secrets about his family, his heritage, or some sort of magical items or powers that were meant for him. It might also reveal things about his parents' past and their relationships with other characters in the wizarding world.
She might be overjoyed. After all, Naruto is her son. She could immediately rush to find him and embrace him tightly, tears of happiness streaming down her face.
In this fanfiction, Harry might have a magical encounter where his parents' spirits guide him. Maybe they reveal secrets about his family's past that Dumbledore had been keeping from him for his own protection.
One possibility could be that in this fanfiction, Harry's parents are in some sort of magical stasis or hidden away. The Dursleys, perhaps forced by some magical contract or under a spell, reluctantly take Harry in while his parents' situation is being sorted out. This could lead to a very different dynamic than the canon, with Harry constantly longing to find his parents and the Dursleys being more on edge as they have to deal with a magical child while his powerful parents are still in the picture.
One idea could be that Naruto discovers his parents are alive during a mission. Maybe he stumbles upon a hidden village where they've been in hiding all this time. This could lead to a very emotional reunion as Naruto has always felt alone without them.