I agree. The windbreaker was because Jenn loved it being 90s style. I don't think J cared or he would have insisted on a purple bike helmet, right? He got a blue and green one. Although he did seem interested in that pink one because Oliver was interested in it and Jenn pointed that out.
My personal belief is that things like clothing or toys shouldn't be assigned to a specific gender based on color or design. Like you said, kids like what they like. I have seen how teen boys these days like purple or pink hoodies or clothes, slides, etc. And nobody should care or make it a big deal.
But also Jenn is just annoying with her emphasis on J liking these things that are labeled for girls, like it is some novelty thing she can share about him to seem more like a "modern" cool influencer mom. Just let him like what he likes and don't explain it and don't show it off.