Vesuvan Doppelganger enters play as a copy of
Voice of All, and the controller chooses Blue. Then, Vesuvan Doppelganger's upkeep ability makes it a copy of a Bear Cub, and then back into a Voice of All. Does the Doppelganger still have Protection from Blue?
607.2d. If an object has an ability printed on it that causes a player to "choose a “ or ”name a card“ and an ability printed on it that refers to ”the chosen ,“ ”the last chosen ,“ or ”the named card," those abilities are linked. The second ability refers only to a choice made as a result of the first ability.
607.5. If an object acquires a pair of linked abilities as part of the same effect, the abilities will be similarly linked to one another on that object even though they weren't printed on that object. They can't be linked to any other ability, regardless of what other abilities the object may currently have or may have had in the past.
706.7a. If an ability causes a player to "choose a “ or ”name a card,“ and a second, linked ability refers to that choice, the second ability is the only ability that can refer to that choice. An object doesn't ”remember“ that choice and use it for other abilities it may copy later. If an object copies an ability that refers to a choice, but either (a) doesn't copy that ability's linked ability or (b) does copy the linked ability but no choice is made for it, then the choice is considered to be ”undefined." If an ability refers to an undefined choice, that part of the ability won't do anything.
Came up in the judge chat, we were pretty sure that it can't possibly remember the choice, but there may have been an old ruling involving
Skill Borrower that muddied the waters. Thanks!