This I honestly don't know the answer to. Since you didn't include any references for your claim, I can only take it at face value.
You're more than welcome to post examples. We all know A:A ratios are meaningless. Yes, the book is 2 years old. That doesn't invalidate the information in it. Christ, he has to write a new edition every few years, look up the studies on EVERY SINGLE STEROID, SARM, AI, Fatloss drug, etc and see if there has been any new information/studies/references provided. That's not something that you can do in a few weeks or a month.
I consider it a valid source of quality information. Everything is sourced by studies, all the data is thoroughly researched, and he adds new chemicals, peptides, and whatever else the new flavor of the month peptide or GH booster, or whatever and find quality valid research on these compounds that usually don't exist because they're research chemicals and people are just reading the patent, synthesizing the chemical, and selling it on the open market. But, that's an argument for another time.
It's not going to be completely up to date on every new research as books are a different medium than forums. A lot of stuff on forums is just anecdotal experiments people are testing on themselves. Anything that could possibly increase muscle or burn fat is tested by people who want to be guinea pigs for these compounds that could have been made in somebodies bathtub or kitchen. I prefer to use tested, well studied, and compounds that have been around for a long time and have good safety profiles, and have been used by many thousands+ people for decades. Peptide are fascinating, don't get me wrong, but I'm not going to run out an inject myself with something that's brand new that's never been studied and has no data on it. That's why BOOKS are good as reference material. They may not have the latest brand new study that just popped up, but it has solid data that substantiates the claims he makes.
So, you are welcome to disagree with my assertions, I really don't feel like getting into a whole new argument about it. But, when you look at information that the bodybuilding community has known for decades to be factual and then come along with no references or sources making claims like that, how am I supposed to know if that's true or not? Is there NEW information that shows the beta2 receptors don't down regulate? Or where are you getting this information from?