My husband's psychiatrist is switching his medication right before my birth

I'm 38 weeks pregnant and scheduled for an induction Monday. My husband is schizophrenic and bipolar. He has a therapist and psychiatrist that work together (or are at least supposed to). His regular psychiatrist took a higher paying job and ny husband got paired with a new one. He usually only meets with him once a month. My husband's old psychiatrist was great, always listened, and was very helpful. My husband has been doing very well on the medication he is on now. He has his moments but he is doing way better than he was a year ago. He went to meet with his new psychiatrist and when he came back he had a bag from the pharmacy of new meds and he said his psychiatrist is switching his meds. I asked why and he said he doesn't know. He wouldn't give him a reason, he said he wanted him to stop his medication cold turkey and take this new medication. He's switching new meds so close to my birth. Now before anyone comes at me saying I don't care about my husband's mental health only my birth, thats not the case. His regular meds were working fine. And this psychiatrist can't give us a reason why he's changing his meds or tell me how these new meds will benefit my husband. If he could give me actual good reasons of course I would want him to take them. But to switch meds that were working with no given reason, he will be having to adjust to new meds while adjusting to being a new parent, especially with his mental disorders, it could become a whole mess. I'll be dealing with postpartum and he will be dealing with his mental health as well. I just want to make sure we are switching them for a good reason. My husband ended up calling his psychiatrist and he simply explained our concerns and he wanted to know why his meds were being switch, and instead of giving us an explanation, you know what this man said? "So how many years did you and your wife go to school for psychology?" My husband said "We didn't " and he said "Hmmm... Interesting. " Just such a fucking asshole. He never gave us an answer why he was switching his meds. Instead made us feel stupid and rushed us off the phone. My husband still has some of his old medication and he says he wants to just continue taking that and not start the new medication. I know we are supposed to listen to the doctor, but if he isn't going to give us a reason for why he's changing my husband's meds, why should we be messing with his chemical balance if it has no benefit?