So where is the best place to learn? You can't really rely on research articles alone, because not nearly enough studies have been done on PED's, especially specifically related to physique and performance enhancement, to rely on those entirely. Most social media platforms aren't that great; with reddit, IG, FB, etc.. you have to sift through a ton of BS, and useless trans content in the case of reddit, to get decent tidbits of useful info here and there. YouTube has some decent channels, but you also have to be wary of shills and click bait that praises things based more off of it being the newest thing that'll get views, or peddlers of products that get them affiliate link sales. On this forum, there are quite a few educated and knowledgeable folks that engage in solid discussions on a variety of relevant topics. Is it perfect? No, but with a bit of discernment you can get some useful information here. The thing is, it's not even about whether or not the forums are a great or bad or somewhere in the middle when it comes to learning.
Regarding the intro post; this is a forum with rules and etiquette. If a current or former Mr. Olympia signed up, I'd hope he'd have enough respect to follow the forum etiquette and post a brief introduction in the new members forum. It's about respect, not status, and the attitude that you're above having to follow rules just because they seem arbitrary or outdated, or because of the "do you know who I am attitude" is akin to off duty cops and government officials who get pulled over for traffic infractions and expect to flash an ID and be sent on their way. They don't have to follow the same rules that the peasants do, they don't have time for that, they're important and have things to do and places to be.