We know the the Good Daedra taught the Chimer how to structure their society, but I wonder if the Great House system was completely new to the Chimer or if it existed to some degree in Altmer society.
Since we haven't heard anything about it yet and we know a whole lot about Summerset already, I'd say there's very little chance.
Also, when the Dunmer did follow the Good Daedra, they didn't have the Great House system yet. It was established post Battle of Red Mountain when they had already been cursed by Azura.
Dunmer that still live the Ashlander/Velothi way, that still follow the Good Daedra, despise the Great Houses.
They used to have what are called Kinhouses (hence the name kinlord) but all that got retconned years ago I think.
No one is saying there aren't multiple interpretations of the lore, and we're not arguing that ESO did it "wrong".
We're arguing that they decided to go for the most boring, mundane, seen-before interpretation possible. Like they almost always do, unless they can ride on the coat-tails of past games.