Sooooo what happened to the previous captured cooking teachers? Did they eat them? Gave them to Gauche?

maybe they eat them after gauche is done with them....

Maybe that giant piece of "beef" that Ushibarock cooked was them. I mean with all the weird lupin collection pieces, it is possible one as the ability to turn things into food. And if this piece does exist I hope it is pink and has "buu" in the name.

The show does imply a lot of morbidly dark stuff, which it gets around by simply not addressing them. I noticed a bit of this as well from what little I saw of Zyuohger, the previous show Junko Komura wrote.

Really? What stuff did you see in Zyuohger?

I did remember an episode where a monster was very visibly attacking an ongoing highway.