Let's use the equally arbitrary "Finnish Litmus Test": In the group text they joked that I would go out and play ice hockey all day, only listen to death metal, eat exclusively pickled fish...

Just sounds funny to me. Almost like a history of oppression is an integral factor in this, and joking about the diligence and work ethic of a group that's found huge success via those is different from joking about a group that's been literally enslaved, marginalised, and overtly oppressed by the group the jokers belong to.