It could mean that Naruto has a more powerful and mysterious heritage. His abilities might be even more special than previously thought.
In some fanfictions, Naruto's mother, Kushina, has a special connection with the Kyuubi. For example, some stories might explore how Kushina's chakra influenced the Kyuubi's behavior. Since she was the Jinchuriki before Naruto, her relationship with the Kyuubi could be a rich source of plot development in fanfiction.
He might be shocked at first. Naruto has always had a complex relationship with the Kyuubi, so finding out his mother is somehow related to it would turn his world upside down. He would probably have a million questions running through his head and would need time to process such a huge revelation.
One implication could be that Naruto has a stronger connection to the Kyuubi's power from the start. Since it's his mother, he might be more in tune with the fox's chakra and abilities. For example, he could learn to control it more easily without having to go through as much struggle as in the original story.
Well, Kyuubi might influence Naruto's growth by providing him with a sense of power from within. Since Kyuubi is like a mother figure, she could be a source of emotional support too. Naruto may draw strength from their connection, both in tough battles and in dealing with his own insecurities.
If Naruto is Kyuubi's son in fanfiction, it could mean that Naruto has some innate powers directly related to the Kyuubi. He might not need to struggle as much to control the Kyuubi's power as in the original story.
One implication could be a change in Naruto's power source. If he's the Kyuubi's son, his access to the Kyuubi's chakra might be more natural and innate. He might not have to struggle as much to control it as he did in the original story.
One implication is that Naruto could have even greater power potential. Since the Kyuubi is extremely powerful, being its descendant might mean Naruto has latent abilities that are far beyond what was shown in the original story. Another is that it could change his relationships. People might fear or revere him more depending on their views of the Kyuubi.
One implication could be a different power dynamic. Naruto would have an even stronger connection to the Kyuubi's power. He might also face different kinds of discrimination or fear from the villagers as being related to the Kyuubi.
One implication is that his power levels would be off the charts. Since the Kyuubi is an extremely powerful entity, Naruto would have a whole new set of abilities.
There could be. Fanfiction is a vast world full of unique ideas. A Fem Kyuubi as Naruto's mother would be an unconventional but fascinating concept. It might change the entire dynamic of Naruto's story, from his relationship with the villagers (as they might be even more fearful or respectful considering his mother) to his own self - discovery journey.