It's hard to perceive your "what do you mean?" as genuine, especially considering it wasn't a vague reference. I think you could have asked, "Do you only mean abortion or is there something else?" and communicated your points in a less passive-aggressive "trap" framework.
Additionally, the original point only stated US governments are not protecting women, which is true regardless of your stance on abortion, regardless of the intended target of the law and regardless if it was intentionally targeting, "a war on", women.
"What do you mean?" all by itself doesn't come across as seeking clarification. You knew likely what it meant, and if you really did not know, you gave no indication that the answer was a revelation. This makes it come across as being asked in bad faith. If you'd responded that you had no idea that's what we meant it wouldn't have been received poorly, at least by me.
If you'd framed your question as seeking clarification instead of feigning ignorance I think people would have been less combative.