That information was claimed, and has at least a grain of truth to it (complicated setup), but that information now appears to be unreliable.
Haven’t followed the exact custody of Zanzibar, but A. It’s not *in* Kenya, geographically (island), and B. It belongs to Tanzania. Mostly muslim.
It’s the place Hitler, at an early stage before he had fully conferred with Hajj Amin, claimed to want to send the Jews.