http://www.uesp.net/wiki/Lore:Great_War#The_Second_Arnesian_War and http://www.uesp.net/wiki/Lore:Fourth_Era
The Empire is now a shadow of its former glory. Valenwood and Elsweyr had been ceded to the Thalmor, Black Marsh had been lost to Imperial rule since the Oblivion Crisis, Morrowind had yet to fully recover from the eruption of Mount Vvardenfell, and Hammerfell was plagued by infighting between the Crown and Forbear factions. Only High Rock, Cyrodiil, and Skyrim remained prosperous and peaceful.
The southern half of Morrowind is ultimately conquered by the Argonians. Since Argonia had already left the Empire, south Morrowind was then forced to secede.
After five years, the war ends in a stalemate with the signing of the Second Treaty of Stros M'kai. The Aldmeri Dominion withdraws from Hammerfell entirely.
4E 40s — Red Mountain erupts; Vvardenfell is destroyed.
In Vivec's absence, the Ministry of Truth becomes unstable. Vuhon creates an Ingenium that uses at first dozens of dying souls, then a small number of living ones to stabilize the rock. The soul of Sul's wife Ilzheven was among them. In a fight to free her, the Ingenium is destroyed and the rock crashes into the city of Vivec with all the energy it originally had. The impact causes Red Mountain to erupt and destroys the entire island of Vvardenfell, as well as causing massive destruction to the rest of the province.
So yes, the map looks accurate.