My dad's from Ireland, so this strikes home. I've never learned more than a few words of Irish, but Irish culture and heritage means a lot to me. I lived in Ireland for a year, attending Trinity College and did my high school honors thesis on the intersections between Irish history and Celtic mythology. While they are definitely Irish-Americans who are also racist as fuck, you can share in the culture and work against racism at the same time.

Unless OP lived in one of the few small Irish-speaking enclaves, they would have learned Irish at school as a second language. Wanting the baby to learn Irish as a first language is a very understandable impulse!

I would view the over-reaction of the husband as a clear red flag and would encourage the OP to head to counseling (with or without the husband) BEFORE the baby is born. Figuring out whether this is a sign of stress that can be resolved amicably (Irish is on Duolingo now if husband wants to learn!) or the start of a pattern of controlling behavior is critical.