With little surprise, the mysterious composer teased in Capcom Unity's April Fool's Day Dark Void joke is none other than huge Mega Man fan Bear McCreary. Best known for his works on the recently ended Battlestar Galactica and Terminator: The Sarah Connor Chronicles, he will be bringing his distinct musical style to Dark Void. Check out his interview here:
The Mega Man Connection: McCreary's a huge Mega Man fan, to the point where he arranged the title screen's song in 8-Bit and he codes his compositions with the different bosses of the Classic Series.
Source: Capcom Unity