No, Blac Haze is not Tupak Shakur. Tupac Shakur was murdered in September of 1996. Blac Haze, as well as Mackaveli, have a similar sound to Tupac. Blac Haze's real name is Ted Outler, and he is from the Florida Keys. There is not much information available about Blac Haze because he has not been marketed much. There is a biography available for him at http://www.last.fm/music/Blac+Haze/+wiki.
A lot of rumors has been going around ever since Blac Haze released his own music in the past. People have been thinking that he is 2pac, alive and kicking. However, 2pac has already dead for years now. Although Blac Haze's and 2pac's songs are similar, he is not 2pac.