Though Christian Bale and Robert Duvall are capable dramatic actors, the one can not be expected to be a magician, and the other can not be expected to carry a film
in a cameo capacity.
If the character appears
in a cameo capacity, the Captain Marvel film will then serve as a proper introduction, giving fans all they need to know about the character and where she has been for all of this time, before bringing her in Avengers 4 to help in the fight against Thanos.
Not exact matches
With Aykroyd having let slip about a
cameo, it now seems that the notoriously hard to pin down Bill Murray will also be showing up
in some
capacity.
Mario appeared
in Nintendo's first tennis game, originally released for the NES and later ported to the Game Boy; there, he only appeared
in the
capacity of a
cameo as the referee.