An all-important comma here: “In the event, they were not needed...”
I read this as the fighter planes were there to take out any attempt to shoot down the missle(s)? that delivered the actual strike.
I paused a long time at this particular phrasing and wished the author had elucidated his point.
Air to air missiles are not very capable against surface to air missiles. The guys flying air cover were there in case Syrian MiGs came out to play, which they didn’t.