This is the story Gab likes to tell, but is anyone actually considering it critically? Twitter is full of out-and-proud white nationalists. Its AUP restricts violent and harassing hate speech, going out of its way to refine the definition to targeted harassment. Richard Spencer has an active Twitter account. For that matter, so does Gab itself, which until recently was also an out-and-proud white nationalist account. Gab has a blue checkmark!
What seems to have happened with Gab is that its founder got kicked out of YC for harassing batch-mates, got some publicity for that, and decided to use it to capitalize on the "alt-right". Is there any indication anywhere that Torba is doing anything more interesting than trying to sell neo-Nazis a monorail?