I never stopped to wonder what happens to fish when calendars and forecasts project a "bad fishing week". This can happend based on the moon/tides/winds, the effect is less successful fishing, but what are fish doing?

Are fish more scattered? Feeding less? I assume tey need to eat no matter what, and I speculate maybe they are just less aggressive at specific times, or have moved further out. But they sure can't go on a diet.
What is the consensus?

Don't depend on any of that.
The fish are still there.
The best time to go fishing is whenever you can! I've caught just as many fish here on the gulf coast of florida on "bad days" as I have on good ones.
Grab some shrimp and go get em!

Fish read the calendars as well, and on bad days they gather and hold raucous parties with all of their friends.

Some of my best fishing days have been poor fishing days on the calendar. The only thing to realize is that on days with higher tidal swings, especially if you're in an area subjected to large tital swings, is during the full rip you'll need more weight to get down, or may be unable to get down. I've fished out of Homer on a 20+ foot tide and was unable to hit bottom with a 5# sinker. On the flip side, bigger tides stir up the bait fish and can result in the predators more actively feeding and hence better fishing.

Timing your trip so that you'll be traveling while the tides rip and fishing closer to slack tide isn't a bad idea.