Bro,, in what world is a comment making a joke about how this sweater would make a good gift for someone who's nursing objectification/sexist/misogynistic...? Getting a friend a nursing bra is a normal thing to do, and making a joke that this is even easier than a nursing bra is well within the realm of normality.
You don't know OP nor their relationship with their coworkers. You're just applying how YOU would feel if it was you to this situation, but guess what? It's not you
I know woke is back after the election, but holy shit you're getting downvoted into oblivion on probably the most progressive online community I've ever participated in. That should be an indication of how off base you are here.