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.

So, if machines will be decent servants to the cats, will humans get x-ed out of the equation?

Basically when the "minds" are benevolent deities all scenarios are possible including this one. We can spend our time with cats, we can even turn into cats...as he writes about "Changers" who genetically alter themselves or shift species at whim.

And as always if someone acts up and violates the Golden Rule they get a slap drone: https://theculture.fandom.com/wiki/Slap-drone

25M - 18.5M years ago.

With modem technology it became feasible to observe cats without disruption and it showed communal behaviours, including communal care for offspring and IIRC even bringing food to share.

All along the line of somewhat transitionally joined communities instead of more stable groups

If you haven't already, read "A Dream of a Thousand Cats", one of the Sandman stories. It was also adapted by Netflix as the last episode of season 1 of The Sandman.