That was my first conclusion, too - the absence of something in the fossil record does not mean that it was not there, just that it did not fossilise.

For one, predators in general often have more gracile build, high power to weight ratio - and don’t fossilise well. They’re also much rarer than herbivores, of course. This means the signal in the fossil record is much weaker and any deviation seems much greater, as you have to turn up the gain to get meaningful data.

Perhaps cats during that period were predominantly dry desert hunters - it is a common niche for felidae - and that environment produces checks wristwatch few fossils.

Perhaps there was another critter extant during that period that just found the crunch of cat bones irresistible, and they all got scavenged.

Perhaps they developed culture and cremated their dead.

Dunno. All that said the E-O was a big transition and it likely did result in gigadeaths, and predators would have been harder hit, ultimately and proportionally.

Similar thoughts crossed my mind as well. But then there's the repopulation with a species that can be traced from Asia. The pre-gap felines just aren't part of the post-gap set. If some were descendants of some endemic low-fossilization branch, chances are they'd be connected across the gap through similarities.