Should I reach out to my brother and what should I say

My brother is 18 now and we haven't talked in a long while. He's been in college. I have a family now so we aren't mad. We are just really busy. I'm 10 years older than my brother but we didn't grow up together. I grew up living with my dad and bonus mom(who I call mom). Me and my mom had a hard relationship because she didn't like that I called my bonus mom mom and she was always so critical of me. My mom has a husband who is my brother's biological dad and when my brother was 12 they were being investigated by CPS because my brother had told his therapist that my step dad had SA'd him. My brother has been SA'd in school by a teacher when he was 5 so that's why he was in therapy.

When the investigation was closed my mom said she took my brother to 5 different therapist and they all said he was lying and then he admitted to lying which we all scolded him for. I haven't spoken to my mom in a while. I know my brother moved out because he said my mom was abusing him and he's living with a friend. Life got busy. We haven't talked. My husband sends me a link on Facebook today about my stepdad. My step dad is Native American so this all took place in the tribal court but he was sentenced to 30 years in prison after pleading guilty to incest, child sexual abuse, and coercion and enticement of a minor.

I read the whole thing and he admitted to threatening my brother. Bribing him with toiletries and clothes and other necessities and other horrible shit. I saw my aunt comment on it and how my mother is just as complicit in this so I reached out to my auntie and she gave me more insight on that investigation. My mom has lied that 5 therapists all said my brother was lying. What happened is she kept taking him to different therapists until she got the answer she wanted.

It's been a while since we have spoken. I want to reach out but should I and what should I say?