It wasn't meant to be a serious attack on his political positions back then.

It was a skit poking fun at his tendency to make grandiose and self-centered statements.

Noone actually thought in 2009 that he held right-wing political positions. That made the skit possible because neither the two artists nor fans were thinking it insuated Nazi ideology.

It was just clean fun mocking his vague narcissistic bullshit.

The added irony is only perceived from the future. The perceived accusation (then without substance) wasn't actually implied back then, it was too outlandish.