Read the link and you shall find the answer.
All Griffin and Klein had to do was put 'parody' or something similar in the name. But they chose not to. Klein's 'comedy on Twitter is dead' response to being banned for failing to adhere to a very clear and simple rule is an amusing overreaction, but then he is a YouTuber and drama is his lifeblood.
If there's going to be any rule changes I'd rather they start releasing old usernames from long-dead accounts.