This is probably where Wmm takes a stand against the collective consciousness by the looks of it:
The next time you hear someone mention the term "Mandela Effect" as being coined by Fiona Broome to describe a collective false memory or alternate reality, please remember that Ms Broome hijacked the term whatever you think about the success of Nelson Mandela's aims or how ever many times people think that he died!
Perhaps there are memories from parallel universes coming through from wherever but don't make the use of this "Mandela Effect" term any more confusing.
A reasonable definition of the original use of the term can be found in this paragraph below from "Leadership for a Better World: Understanding the Social Change Model of Leadership Development" By Susan R. Komives and Wendy Wagner (hopefully it's not from a no longer existing parallel universe)
"Porras, Emery, and Thompson (2007) describe a concept they call the “Mandela Effect,” “when you can create enduring success not because you are perfect or lucky but because you have the courage to do what matters to you. (p2 of Success built to last: Creating a life that matters.) The Mandela Effect derives its name from Nelson Mandela, who led the sometimes violent struggle against apartheid in South Africa. Following his release from 27 years in prison, he convinced those involved in the anti-apartheid movement to change from a hostile approach to one of reconciliation and healing. This was not easy. It was a risky proposition and took great political skill to convince his followers to change tactics. Rather than continue the anger that was tearing the country apart, his ability to convince the African National Congress to negotiate with South Africa's White elite resulted in the first multiracial democracy in South Africa. The lesson of the Mandela Effect is that the power to create lasting change results, in part, from a person's deepest values being reflected in his actions."
If these ideas about memories from a parallel universe out to be as a result of Nelson Mandela's attempts to change Apartheid, then ignore this message, but otherwise you can tell Ms Broome where to stick it!