It’s a joke about being the victim of genocide.
In this case the equivalent joke would be a holocaust joke, which would probably get you fired even faster.
Legitimately, if they’re American, the people in HR probably wouldn’t even believe you if you told them about what actually happened during the Irish famine, or how England treated them for decades directly leading to “the troubles”
They would assume you’re making it up.
I’m not joking
I was more or less taught in school “oh well it was an oopsie-woopsie, all the crops died but England tried to help them! Oh well, such a terrible natural disaster.”
I didn’t learn about the darker side of things until I read into it outside school.
The US education system is a joke.
Curious. I wonder if the region you grew up in influenced this at all… as I am from an area full of ethnically Irish folk whose roots trace back to emigres during the famine, and we definitely were taught that the bloody English were to blame!