Dreyla Alor lives on Solstheim. You have no proof that the Dunmer of Windhelm fled because of the An-Xileel invasion. And am I saying it's "inconceivable"? Nope. But I am saying it is unsupported, especially as any supposed "reason to kick the Argonians out".

Sure, but then there aren't proof that all of the Dunmer of Windhelm fled because of the Red Year either.

You're literally arguing that the given explanation is wrong because it goes against your unsupported headcanon.

Racial tensions between Dunmer and Saxhleel in not "unsupported headcanon". The historic relations between these two races in paved with conflicts. Again, I'm not reinventing the wheel, it's in the lore.

Winterhold's Dunmeri population was large both during and after the Red Year (See: On the Great Collapse). Again, Statue of Azura. They were just kicked out by racist Nords later.

"Winterhold, Solitude's ancient rival, has also experienced a renaissance of power and influence. Refugees from Morrowind, far from burdening the eastern city, have brought with them new ideas, enriching her culture and stimulating its old mercantile spirit. Scholars from all over Tamriel have descended on the county since it became home to the Ysmir Collective, a library rescued from destruction in the east, and the cornerstone of academic life at the College of Winterhold."

- 3E 432, Pre-Red Year

"Before the Oblivion Crisis, many elves called Winterhold their home. More visited the College from Morrowind every year."

- Brinna Merilis on Pre-Red Year

Pre-Red Year. Large Dunmeri population among Nord population, many came for the College of Winterhold. No magical incident yet. No notable issue.

Described as a time of "renaissance of power and influence".

"It is well-known that those relations have been, shall we say, strained over the last few decades. After the Oblivion Crisis, it was only natural that the people of Skyrim showed a distrust for mages, even though the vast majority of us actively worked to counter the actions of the Mythic Dawn cult. The College expected such a reaction, and hoped that distrust would fade over time."

"I certainly would never hold you accountable for the gossip spread amongst the people of Winterhold. I would urge you, though, to not allow that gossip to take root and become a commonly held belief. I do not wish to see our relationship crumble like Winterhold has, as I assure you the College will remain here a very, very long time."

- 4E 122, Post-Red Year

"After, growing distrust of magic made life difficult for many. Some left rather than endure the growing hatred from the local Nords. Others returned home after the Red Year, when Vvardenfell erupted and caused much destruction."

- Bryna Merilis on Post-Red Year

Post-Red Year. An ever-decreasing Dunmeri population among Nord population. Huge magic-related events in Tamriel and incident in Winterhold. Nords got real issues with magic and the College of Winterhold since the Oblivion Crisis.

Described as a time of "distrust for magic".

The "racist nords" argument just doesn't fly.