You're basically just proving my point. The first half is "irrelevant", as you said, or "unrelated", as I said. You're filling in gaps from the first half to the second half.
The post goes (paraphrased): It seems like an oversight to not have this feature of having individuals in multiple households. It got me thinking. Companies can choose not to hire you if your parents weren't married.
You've filled in the "it got me thinking" with "....they encountered this issue with a minor thing, started reading up on it online, and when digging into that kind of stuff ended up reading on what the legal situation is...."
That's exactly what I said is the mental gymnastics in response to OP's question, and you're filing it in like they actually explained it.
Watch your cornhole, bud.