There was an event where the players could decide which of the four tribes controlled the city in Ixalan, does anyone know who won? Or is it still going?

Sun Empire won. There were accusations of the scenario being rigged, but I don't know if they had any basis in reality. They showed us all the alternate endings, at least. Vampire ending sucked; even if they won, they would have lost thanks to the karmasaurus rex.

Vampires were screwed from the beginning because people like to go "Oh that resembles these historical people I consider the bad guys so any attempt to not show them as pure dark morally black monsters is actually saying this historical group was 100% in the right."

Yeah I didn't like the politics / morality of Ixalan that much, the evil pirates who steal and destroy were presented as just having a bit of harmless fun or even as rebellious heroes for fighting against the vampires