In my opinion EEVblog forum doesn't meet the definition of point #1. It has to tick all those boxes, not just one or more of them. The primary purpose of this forum is to exchange technical information, data, assist learning, etc...
1) I don't think your distinction between social and technical media will fly. The interactions and reactions by individuals on this forum are social. "Be excellent to each other."
2) In the US, Section 230 of the Communications Decency Act of 1996 protects social media companies from legal liability for most user content. It might be a serious mistake if EEVBlog argued it was not social media and won as it would lose that protection.
I disagree.
You need to consider the wording of the legislation. "Sole" or "Primary purpose" is very important here. EEVblog is much more than just this forum. No matter how social or anti-social this forum is, it still doesn't meet that definition. If it would, that would mean the likes of Lawrence Systems' forum would be considered social media (which of course it isn't).
I don't even think that the Australian telecommunications forum, "Whirlpool", which is just a forum, would even meet the definition. I don't think there would be a single court in Australia that would agree that it was.
Secondly, application of US law would rely on the definitions under that law, not what another country considers to be "social media". Besides, I don't think Dave is worried about US law. EEVblog is governed by Australian law, first and foremost.