Islam is at the heart of an emerging global anti-hegemonic culture that combines diasporic and local cultural elements, and blends Arab, Islamic, black and Hispanic factors to generate "a revolutionary black, Asian and Hispanic globalization, with its own dynamic counter-modernity constructed in order to fight global imperialism. (say what!)
The term blackface typically conjures up images of performers (both white and black) with caricatured African features in a style which in recent memory was best embodied by Al Jolson. Billy Crystal's performance was definitely not that, but it does bear a family resemblance.
One fact, which should be noted is that Crystal doesn't just have an isolated love for Sammy Davis Jr. but he is clearly really into blackface and the "performance of blackness" generally. For example, when he was on Saturday Night Live, in addition to his many Sammy Davis Jr. impressions, he did a short "mockumentary" with Christopher Guest in blackface as a retired ballplayer in the Negro Leagues.