The current Mandela Effect is a political reality; not a misremembered fact.
Since Mandela's long walk, South Africa's regime change has been from one of White apartheid racism to one of Black genocidal racism.
That is one political effect that Mandela had on SA.
It's not exactly like it's a difficult term to look up.
No matter how much you dodge it, it's not going to change the meaning of it. It's a widely used term, no one is going to change it on account of somebody misusing it erroneously.