So what would the cats choose in the wild?

Canned (and cooked) tuna, mussels, shrimps, reindeer, rabbit, beef etc of course. /s

Given that pretty much everyone just buys canned pet food or kibble at the store, and most of those are made out of whatever is left over after slaughtering animals for human consumption, the whole point of "forcing your cat to eat against its natural habits" is somewhat moot.

CO2 reizt die Schlaumhäute extrem. Schüttel mal eine Wasserflasche gut durch, mach sie auf und halt dein Auge drüber. Die Tiere erleben das nur am ganzen Körper und um ein vielfaches stärker. SOKO Tierschutz hat Videos entsprechender Anlagen auch auf YouTube, da ist nichts mit "schonend".

like she was presenting a decayed corpse

I mean.. it quite literally is a ground up corpse. Given this is McDonald's, I wouldn't be surprised if it was a little decayed as well.