Orihime would probably be over - the - moon excited. She's always been a kind - hearted and emotional person. She would immediately start knitting baby clothes or making cute little charms for the baby. Chad would be very supportive as well. He would offer his strength to protect Rukia during her pregnancy. Uryu might be a bit more reserved at first, but deep down he would be happy for them. He might use his Quincy skills to create some sort of protective item for the baby.
Chad would be a very protective and gentle presence. He would be like an uncle to the baby, always ready to pick the baby up and play with it. His calm and strong nature would make the baby feel safe.
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.
Ichigo might initially be in shock. He could be unable to believe that Tsukishima, who might have been a friend or at least an acquaintance, has turned on him.
Chad would be excited and happy for them. He's always been a loyal friend to Ichigo, and he would see Yoruichi as a great match for him. He might even offer to help with the wedding preparations.
Rukia would probably be very suspicious right away. She knows Ichigo well and would notice the strange changes in his behavior. She might try to confront him and figure out what's wrong.
The Soul Reapers in the Soul Society would see Ichigo as a major threat. They would likely mobilize their forces to either capture or eliminate him. Captains like Byakuya would be disappointed as he had come to respect Ichigo to some extent, and now would see him as a traitor.
Rukia would probably be one of the first to be both shocked and amused. She might tease Ichigo a bit at first but then quickly get serious about helping him. Chad would be very accepting and offer his protection as usual. Uryu might be a bit more skeptical at first, thinking it's some kind of new Hollow trick. Orihime would be very empathetic and try to make Ichigo feel comfortable in his new form, maybe even offer to make some new clothes for him to fit his new body.
Their friends would be really excited. Chad would probably be happy and offer to help with any heavy lifting or physical tasks around the house for when the baby arrives. Uryu might be a bit more reserved but still show his support in his own way, like making some special baby clothes. Rukia would be thrilled and would be constantly visiting, giving Orihime advice on motherhood.
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.