Ingen behåller koncentrationen på en Wild Magic-effekt.
Detta återspeglas i den officiella PHB Errata :
If it normally requires concentration, it doesn’t require concentration in this case; the spell lasts for its full duration.
Detta framgår vidare av flera designer tweets , särskilt:
Paul Cloud @CloudOfDaggers @JeremyECrawford Does a wild magic sorcerer need to maintain concentration on spell effects created by a wild magic surge?
You don't need to concentrate on spell effects from the Wild Magic Surge table.