It seems poorly worded. I think they were trying to say that the person's interpretation of what happened is a fact. Basically that someone can't handwave away how a person says they feel as if it's not true; how a person says they genuinely felt about something is true to them. I assume it is supposed to be targeted towards estranged parents who constantly dismissed their child's emotions and literally cannot understand how that is a bad thing to do.

I took it to mean that feelings are facts - meaning the parent should take it as a true statement about their child’s feelings and not try to argue with them about why their feelings are wrong.

Not well phrased at all.

They are saying that the persons subjective feeling is in fact subjective, and if just because you didn't mean it that way doesn't mean that that is how it's interpreted.

Its manipulative, its like making someone cry and then telling them feelings aren't facts.

It's doublethink. They've been peddling it for like decades now.