Um ... it is in the wiki.
Basically Morrowind is gone, as in ... gone. City of Vivec destroyed, volcano blown, etc. All gone.
Would love to see an updated official map of the hole that used to be Morrowind though.
And this is why never reading the source can lead to an incorrect answer.
Morrowind is NOT gone, rather Vvardenfell had Red Mountain blow its top, covering it in a few feet of ash even 40ish years after it exploded and the obvious lava. After that, the dunmer were pushed out of Morrowind by the argonians. To note, this was a long series of events that were just not the dunmer's years. They were raided by nords and orcs, a small civil war (if you let unofficial dev works count), the the Oblivion Crisis came (Redoran was horrifically beaten badly, and only Telvanni could slow it down, but not stop it), and the Ministry of Truth fell which caused Vivec City to become a crater and cause Red Mountain to erupt.
Since the latest TES book, ~40years after Oblivion, the argonians only incorporated portions of southern Morrowind as a part of Black Marsh. Likely, they were lands being disputed between Black Marsh and Dres.
And before all of you go complete and utter dunmer fanatic, this was judgement from Vivec.Your kind forgot Love. And banish all notions of honor. The dunmer's combat doctrine is all about fighting dirty, and that was one of the lessons Melphala taught the Chimer for [censored]s sake. Plus, it's only Redoran who thinks highly of a Cyrodiilic-ish code of honor, and even then, they were badly devastated from raids by nords who also brought orc buddies with them, and the Oblivion Crisis.