Modern Warzone points out that the name is provisional but apparently developed and publishers would be discussing the possibility of keeping this name for the full product. The new COD is developed by Sledgehammer Games and will be the first original game of the studio since 2017, the year of release of the acclaimed Call of Duty WWII.
Sledgehammer Games in recent years has guaranteed support to the other studios in charge of working on the series and in the meantime has continued work on its own project, apparently a sequel to Call of Duty WWII, apparently also a new Call of Duty Advanced Warfare is being studied, hypothesis later abandoned.
Call of Duty WWII Vanguard should be set in the 50s, but at the moment we have no other details, if not the confirmation of the integration with the Battle Royale free to play Call of Duty Warzone. The announcement should be scheduled for this spring but it is not excluded that it may shift to the summer months, as happened for the reveal of Call of Duty Black Ops Cold War last year.