What is the role of "won't have had" here? In this sentence it doesn't look like a reference to the future, although it is exactly what the will-form usually indicates. Based on the context, the action has already taken place. So I don't understand the logic behind the use of "won't have had" in this particular case.
The sentence itself:
"When Utah’s Republican lawmakers decided to clamp down on ‘pornographic or indecent’ texts, they won’t have had the Old Testament in mind."
The sentence is the headline of one of Guardian articles.