Should we have to cancel our family vacation?

My husband and I have planned a vacation in June. We decided to take the whole week off for a family trip. When we planned this vacation it was last year in September. Well about a month ago my stepsons mom signed him up for baseball. We got a text saying “I just want to let you know blank is now doing baseball Mondays and Wednesdays.” She never asked or even talked about it with us. We are on a weekon/ weekoff schedule. We’ll my husband told her that we had a vacation planned and that he unfortunately won’t be able to make it for that week. We’ll she flipped a lid on him. Like excuse me but you didn’t even ask us if we had plans. We made plans months ago. His step-dad and mom run the baseball team, so they had to have been planning this long before she told us. He even told us that they were running it, but he was supposed to keep it a secret from us. Then he said that he cannot miss those games because that’s embarrassing for him when his step-dad is there and he isn’t. Which I’m sure it’s the other way around. Anyway we have everything ready for this vacation and I plan on going but I feel horrible because it’s making him feel bad. I think he’s afraid of getting yelled at by her. What would you do?