I don't really know, but I suspect that many would be horrified by the deliberate use of American military force against American civilians, no matter how good the argument for it. (Arguably, it would actually be use of force against the terrorists with inevitable civilian casualties, but I suspect many wouldn't see it that way, and many who did would still be horrified.) And all a cover-up requires is that someone judge the same way (or just think it likely enough), justified or not.

Do also consider the fact that even if the story of flight 93 occurred exactly according to the official story, the heroic passengers saved zero lives. Jets had been scrambled. Shoot down orders had been given. The flight was not going to hit its target.

Yes, the passengers may have been heroes in the sense that they did not "freeze up" and tried to save themselves or (possibly) others.

Yet the most popular story presented by the press and government, and lodged in the public consciousness, is that the passengers prevented a final strike.

Realistically, they may have prevented a fighter pilot from having to commit an act that could have scarred him emotionally.

So, yes, I am confident the event was "spun." The question is to what degree.