I don't believe the SA-67 is the most-likely weapon used, here. Given that it's turbojet powered, that missile is almost certainly subsonic and better suited for taking out prop-driven drones like the Predator. Even at sea level, the F-15E would probably outrun it at low cruise speed.

You're definitely right that passive seekers are playing a huge role here, though. Many people online (and on HN) bought into the air dominance shtick just because major radar sites were taken offline. It was always the road mobile and TELAR vehicles that would be a threat.