If the Delayed Linked Ability references the source of the abilities, its window will be as long as the source is in an appropriate zone.
§ 390.5.b Core Rules PDF (officieel)
§ 390 Delayed Abilities are a type of Ability that specifies a window of applicability during which they are active.
§ 390.5 Delayed Linked Abilities are Linked Abilities that are generated by another Ability and reference that Ability or Game Objects it affects instead of a window of time.