No you cannot add anyone to a group as it was then, that has been changed
There are still NAMBLA pages up as groups on Facebook, I just checked. Some are open to join, in other cases you have to request it. Been that way for many groups for awhile. also there is a recent article questioning just what Facebook keeps in their data stores even if offline or secreted. Unless you ask to have all your data remove they keep it all. I was a member of a study group on Hebrew Bible roots and they finally left Facebook as they were being harassed on content about the Bible and Torah!
Last, if it had no legs then Forbes would have pulled it down under pressure from Facebook. It is still there on Forbes site, take from that what you will. But private groups by request only and hidden have existed there for a long time
Either way, Facebook steals your info and pictures, it’s in the EULA and only since regulations changed have they allowed you to delete it all. They moved 1.5 Billion files over to the US to try and avoid GDPR regs and got called on it.
And the title was from Forbes, not me, take it up with them
At the time the article was written, you could add other people’s names to your group without them taking any action on their own.
Further, the Forbes writer did address this accurately, but then he or his editor went on to put that terribly misleading headline on it.
The NAMBLA joining mischaracterization, is a very charged accusation. It carries a lot of negative things along with it. Despite my dislike for Zuckerberg, it was clearly an unprofessional and likely actionable move to place that title on the article.
I agreed with another poster who seemed to be telling you the same thing. I tried to point out the Forbes error to you, concerning the situation in the time frame of the article being published, 2010.
You in turn have tried to tell me what Facebook is like today. That isn’t the issue.