I'm clearly out of date on these sorts of things, I thought that SJWs were insisting that the Irish could never face discrimination, ever, since they're white.
That too. They don't always present a unified front.
Correct. The ones who declare that the Irish could never face discrimination will say the same for the Sami, as they feel that it's pure "white vs. POC" everywhere in all historical periods. Any evidence to the contrary is plainly ignored.
THESES guys, though? They see and acknowledge the evidence, but they're unwilling or unable to admit that their world view is biased. So instead of changing how they look at the world, they try to just slightly edit it to incorporate the new evidence. Instead of declaring that "white vs. POC" is incorrect, they declare "Certain white people are POC".