We don’t know much about Strixhaven at this point.Except for that Strixhaven is the name of a school, on a new plane of which we don’t know the name yet.
I do have my suspicions that these 3 cards from Commander Legends feature the Strixhaven plane (whichever plane that is)! /hype
New Keyword Abilities
Chances are that Spark is a new keyword ability in Strixhaven. This ability has been previewed on a Mystery Booster Playtest card called Blood Poet. Ofcourse, the implementation of the Spark ability as featured on that card might have changed over time, even the keyword’s name might have changed.
Things we know about Strixhaven (with source):