Boyfriend parents don’t want to come to our gender reveal

My boyfriends parents are Christians, my parents are just like anybody else’s. My parents aren’t ghetto or anything, they’re good people they just go with the flow. In other words they let people be them & are less judgmental about it. His parents don’t like that. He told them yesterday that we were having a SMALL gender reveal for our baby most likely at my house. We live down the street from one another, literally like 3 mins apart from each other if your walking. His parents told him they weren’t coming because they feel like gender reveals are for young people (I’m sure they probably said more but my boyfriend didn’t tell me) my thing is the gender reveal isn’t about anyone else but me, their son, & our baby. Even if they just came just to see the gender & left that’s fine but to not come at all is ridiculous. It will be 4 years on the 27th since we’ve been together & I think it’s time our families got together (specifically our parents) especially since we have decided to bring a baby into this world together. It’s not like his parents are older than my parents because they’re all around the same age. To me it’s about support & for them to not be there would be weird. Like how many more events will they miss under these stupid circumstances? Am I overreacting?