His father might be extremely proud. After all, Goku has achieved so much, like protecting the Earth multiple times. He would look at Goku with admiration for his strength and kindness.
Gohan would be really surprised, but being the kind - hearted person he is, he would try to understand and help out. He could offer to train with them in a more gentle way to keep them fit during the pregnancy. Piccolo would be more of a silent observer, but still be there in case of any threats.
The reaction among fans would be quite mixed. Some die - hard fans of the original series would be appalled as they have a clear image of ChiChi and Goku's relationship. They would see this type of fanfiction as a perversion of the original concept. On the other hand, there are those who are more open - minded and might see it as an interesting, if not controversial, exploration of the characters. But overall, the negative reactions would probably outweigh the positive ones.
Goku would be a mix of angry and worried. His Saiyan blood would make him want to rush into battle with Raditz right away. But he also knows how dangerous Raditz is, so he might first try to gather some allies, like Piccolo. He'd be constantly thinking about Gohan and how to rescue him as quickly as possible.
Twilight would be excited to explore a new fictional universe. She'd start taking notes on the magic systems and different worlds in the fanfiction. Rainbow Dash would be bored if there wasn't enough action. She'd be looking for epic battles and heroic deeds. Pinkie Pie would love the fanfiction just for the fun of it, no matter what it was about.
Goku would likely be extremely excited. He has always had a longing to know more about his Saiyan heritage and his father. Meeting Bardock would be like a dream come true for him. He'd probably ask a million questions about his past and Saiyan culture. Chi - Chi, on the other hand, would be a bit more reserved at first. She'd be polite but also a bit cautious, as she doesn't know what this Saiyan from Goku's past might be like. But as she sees Goku's joy, she'd warm up to Bardock.
Chi - Chi might also be heartbroken. She loves Goku deeply despite his flaws. In fanfiction, she may initially be in denial, thinking that Goku will come back soon. But as time passes, she realizes that he may not return, and this could lead to a deep sense of sadness and loneliness. She has to then figure out how to raise their children on her own.
In fanfiction, the reactions in the Pokemon world to FLIM from MLP would be diverse. The Pokemon that are friendly and trusting, like Eevee, might initially be drawn to FLIM. However, as they get to know him better, they might realize his true nature. The villains in the Pokemon world, like Team Rocket, might see FLIM as either a competitor or a potential tool. They could try to use his skills for their own evil plans. Meanwhile, the regular citizens of the Pokemon world, such as the people in the various towns, would be cautious. They have a peaceful life, and FLIM's arrival with his business - minded and sometimes sneaky ways could disrupt their normal routine. So they would keep an eye on him to make sure he doesn't cause any problems.
Twilight Sparkle would probably be devastated. She looked up to Celestia as a mentor, so she might go into a state of deep mourning at first. But then, she could be motivated to try and fill the void Celestia left, using all the knowledge Celestia had imparted to her.