Maintenance for the week of January 12:
• [COMPLETE] ESO Store and Account System for maintenance – January 14, 9:00AM ET (14:00 UTC) - 12:00PM ET (17:00 UTC)
I can see why they might have decided not to implement the ANtique Map of Cyrodiil - forcing people to run through PVP areas, and potentially get attacked by other players while they are unable to defend themselves because of being in the Antique Excavation screen.
But I can't see any good reason for not having implemented an Antique Map of Western Skyrim, as an item sold by general-goods Merchants, like all the rest of them.
The only other place that has no Antique Map is the Clockwork City, and there are tons of reasons why an antique map of that wouldn't be appropriate in lore...