My recollection of Kitchen Confidential was that he was specifically to seafood. Whereas many major fishmarkets are closed Sunday and Monday, so Monday night's fish special is leftover from Friday or Saturday. Is this always bad? No, not always. By no means did I take away from this book that you should never eat out Sun-Tue.
I think a lot of what Bourdain wrote about in that book gets blown out of proportion in discussion. Generally, he gave a lot of good tips for bettering your odds of getting a good meal and lowering your odds of getting sick. None of what he said is an absolute and must be considered with reason and consideration.
That being said, there are quite a few things I did take away from his book that I keep in mind (besides the "fish on Monday" thing):
Brunch: Weekend brunch is often full of second-string chefs, leftover food, and second-string servers who do not want to be working on a Sunday. The odds of getting a great meal with great service at a weekend brunch are slim. I subscribe to a similar
school of thought.
Mussels: Bourdain pointed out that he has rarely seen mussels handled properly in kitchens he has seen. I am pretty picky about where I eat mussels and I often quiz the waiter about freshness or how often they serve mussels to gage their response (which is always positive, but it's all about delivery).
Hollandaise sauce: Another item Bourdain mentions as being often handled improperly. Fortunately I figured this out before I read his book, as my wife pointed out to me early in our relationship how I always got sick after eating eggs benedict.
Specials: Beware of specials that sound like something has been done to cover up leftovers. I think fish in a vinaigrette or seafood au gratin were prime examples. You are likely eating last night's leftovers in a sauce designed to mask the lack of freshness. Which is fine, if that's the dish you really want.
Bottom line is that I don't think there's a hard-and-fast rule about when and what to eat. If you're really concerned about certain things, use your best judgment and do what you can to improve your odds.
Best,
Michael