That seems like a pretty ignorant thing to say, that in the sum of all human interactions online, the event OP described has never happened (or is even supposedly that rare). I would like to know why you think that would be true.
It certainly exists and I truly envy the fact it hasn’t affected your life yet. n=1 but it’s affected mine as a recent college graduate and person who works in FAANG.
There's a good example of just this thing happening right here[0]. A group of young climate activists disbanded because despite the good work they were doing they decided their group was too top-loaded with white people and should be led by POC.