The Thalmor hate the Dunmer with a passion in the end, should the Thalmor go far enough and fail to unbind the world a war with Morrowind is inevitable. Still I think they would concentrate more on destroying Talos then on destroying Morrowind.
Truth is, this matter confuses me, and regardless of our opinions on it, a good writer could have the Thalmor attack Morrowind by giving them a solid reason to do so. I've come to the shaky conclusion that attacking Morrowind would be one of the last things the Thalmor would do during their grand military campaign, but it's still on the list.
I agree that Vivec is not a pillar, or was not always one. He is seemingly not one. He
could make himself a pillar though, maybe he's already done that. if I understand the Scripture of the City correctly, The City of Swords was built in his image which is the image of the Aurbis. If Vivec made his city a Tower, then this Tower cannot truly fall unless the stone, Vivec, zero-sums.
"I have rebuilt myself." says the city (Sermon 25). In this case, Morrowind will have the last laugh.
endif. twice.
Eh, just a theory.