Some of them could be entertained. For those who are more open - minded, like Yoruichi, she might find it fun to see the different interpretations of their world and the characters in it. However, others, like Byakuya, might be more critical and think that the fanfiction distorts the original values and stories of the Soul Society.
Ichigo might go into a state of self - reflection. He would wonder if there is something he has unknowingly done to cause this. He would try to analyze his past actions during the time travel. He might isolate himself from his so - called betrayers for a while to think things through. But ultimately, he would not give up on his friends. He would strive to find a way to regain their trust and set things right, because he values his relationships with them deeply.
If Ichigo and Yoruichi get married, it could change the power dynamics in Soul Society in many ways. Ichigo has human and Hollow powers, and Yoruichi has her own unique abilities. Their combined strength would be a force to be reckoned with. This might make the Gotei 13 more cautious about dealing with them. They could also inspire a new generation of shinigami to be more open - minded about relationships between different races, like humans and shinigami. Which in turn could lead to new power blocs forming within Soul Society.
The characters in DxD would be quite shocked at first. Ichigo's appearance and his powers are so different from what they are used to. For example, Rias Gremory would probably be intrigued by Ichigo. She might try to form an alliance with him, seeing his potential as a powerful ally. Issei, being the main character in DxD, would likely be both jealous and in awe of Ichigo's abilities, and might challenge him at first but then learn from him over time.
Ichigo's family on the other hand, would also be surprised. His father might be a bit more open - minded though, given his own strange abilities and knowledge of the spirit world. His sisters would likely be excited about having Byakuya as a brother - in - law, especially if they see how much Ichigo cares about him. Overall, Ichigo's family would probably welcome Byakuya once they get to know him better.
Ichigo's family might be a bit surprised at first. His father, Isshin, would probably be happy in the end though, seeing his son find love. His sisters might be excited to have Rangiku as part of the family and look forward to all the fun they could have together. As for Rangiku's side, if she has any family in the Soul Society, they might be a bit more hesitant. They might worry about how a relationship with a human like Ichigo could work out in the long run, but eventually come around when they see how much they love each other.
Rukia would probably be both amazed and a bit worried. Amazed at the new power Ichigo has, but worried about how it might change him. Chad would see it as a natural progression of Ichigo's power and be supportive. Orihime might be a bit scared at first, but then she would see the good in Ichigo's new form and try to encourage him.
There could be friends who are initially shocked. They might not have expected Ichigo and Senna to start a family so soon. But after the initial surprise, they would come around and offer their congratulations. Maybe they would even share their own experiences of having children or being around pregnant friends.
However, there could also be negative reactions. Some conservative elements in society might be critical and try to enforce traditional gender norms. They could bully or ostracize the boy, which would be unfair.