The name is real, but it appears in neither Bungie's documentation nor the developer's own. Here is where Project Sunrise came from and what it actually covers.

Destiny 3 has never been greenlit, but the search results still say otherwise. We put the rumor timeline in date order, set Bungie's own on-record answer against the leaks, and work out what a realistic release window looks like once you follow the money Sony has already written off.