AIO Partners parents were “disappointed” we aren’t having children

I (32F) have always known I’m not having kids. When I met my boyfriend (33M) two and a half years ago we discussed us not having kids and both of us being totally fine being the really cool aunt and uncle to our siblings if they choose to have kids. This year I decided to make the decision to have my tubes removed to ensure I wouldn’t end up pregnant by accident, what with the current fear of women’s rights in America with our government the way it is. Along with my mother having severe health risks when pregnant, five miscarriages, all before two very premature babies (my older brother at 2lbs5oz and me at 1lb6oz) and needing and emergency hysterectomy, I saw how desperately she wanted to be a mother and knew I didn’t have it in me to go through what she did to be a mother. I know just how difficult it can be and have known how serious a decision it is for my entire life, being a 9month NICU baby myself and having a 1% chance of living after being born at 24wks. I’d discussed my desire to have surgery with my boyfriend and we were both totally cool with the decision, him supportive and me excited. He didn’t tell his parents until the day after I’d had surgery and his dad took him to dinner and made comments about how it “wasn’t permanent” as in, I’M not permanent, because the surgery sure is! Now just to be clear- I have a pretty long list of why I don’t want children, but also he had stage 2 testicular cancer 5years ago (before we started dating [he’s healthy now]) and had an orchiectomy (testicle removal surgery) as well as doing chemotherapy, so there’s no promises he can even have children naturally! The fears of passing the potential for cancer on to his future children are very real for him, and I think he came to the conclusion that he wasn’t set on having children when he was diagnosed in his mid 20’s. His oncologist highly recommended he preserve his sperm before doing chemo, just in case, because he was unmarried and not in a serious relationship, and also young! He’s a very family oriented man and is so close with his family, especially during a tough time like getting a diagnosis like that. So his parents were very involved in his treatment and the whole process of him getting healthy again, including his mother heavily pushing for him to preserve sperm when the oncologist recommended it. When he told his parents I’d had surgery they immediately blamed me for them not being grandparents (he’s the eldest and eldest son, but his younger sister and brother both want children!) I just can’t wrap my head around how I’m being blamed for this when it was OUR decision and that they didn’t start coming to terms with him potentially not having children when he was diagnosed with testicular cancer and had a testicle removed!!! For the record we live together and have for 2 years, and have already decided we’re getting married, he wants to do the proposal the formal way so I’m letting him do it how he wants, but we know the commitment is there. AIO for thinking they’re being SUPER disrespectful of me for suggesting he just go find someone he could get pregnant and that I’m so replaceable?