A "plopper" is someone who asks a deliberately provocative/controversial question but doesn't return to join in the conversation.
One unintended consequence that ploppers will no doubt see (if they bother to really think about the types of responses that they get) is that there is no "echo chamber" at all. Often their OPs will generate vigorous debate, even though most/many people in the discussion share a common lack of belief that we all have a gender identity.
TBF if MNHQ does set up a Q&A thread to invite questions in advance, everyone is a "plopper" because we're not starting a conversation thread with Baroness Cass: we're asking a question and not interacting further with her response to it.
I agree with PPs who have said that dissenting voices should be included in the Q&A. I should imagine as with all questions, there will be themes emerging. Unfortunately one common theme that still emerges from the "dissent" camp is around the methodology of the research - even the BMA is bizarrely effectively doing its own repeat of the Cass Report to validate everything.... led by a geriatrician. I say "unfortunately" because Baroness Cass has already addressed the methodology question in her public facing Q&A on the Cass Report website. It simply seems that there are some people who don't like the answer.
Edited to reflect that Dr Cass is now Baroness Cass.
Also to add that it beggars belief that the BMA think they can somehow do a better job in one year than Baroness Cass did in four. They'll barely scratch the surface of everything she achieved... especially as their position of "neutrality" starts with the premise that they are supporting "trans children". Perhaps they didn't quite understand what David Bell meant when he spoke about the risk of using the phrase "trans child" and how it forecloses on the outcome of any therapeutic exploration. If so, it's rather worrying - I had hoped that doctors would understand this kind of thing better than random members of the public like me.