Yes. I think there is dark agenda behind it. It is all over youtube now.
Some people actually believe it, but I think that it is headed by people that do not believe it. I think the main goal is to discredit "conspiracy theorists" as a whole.
There are real conspiracies and there are fake ones to make it all look nuts and turn people away from the truth.
The Flat Earth thing is certainly one of the fake ones.