I guess, since she was so fantastic as the Borg Queen, and again they've yet to name her character or list her in IMDB, I just have a really hard time believing that her "small" role will not be very big/important/impactful in a way. It would be a waste of her otherwise. And it seems like Alfyse is really quite unnecessary to the story, from what we know/think will happen so far. they have Malekith to lead the Dark Elves, they don't need a Queen too.
At the same time it's SO likely that Hela would show up, with all the death that's to be expected in Thor 2, and rumors of seeing all 9 realms in some way. And I'm still wondering if she may figure into the Thanos storyline, perhaps not as a lady Death/Hela combo, she could instead just be exchanged for Lady Death as the "love interest" for Thanos in AV2. They certainly made a few different pairings in the x men movies, from what I remember from the comics (for instance, Iceman and Rogue were never an item from what I recall). So they could certainly change some of those aspects of the story to freshen it up and make it more accessible to the general audience. And that also could explain why Thanos may allow Loki to continue to live after his failure, if he is the son of his beloved. Hm?
and on a probably/possibly unrelated note, watching the very beginning of Avengers the other day, when Loki is handed the scepter, I noticed that the hooded figure that hands him the scepter is neither Thanos, The Other, or a Chitauri. That is for certain. There is a pale normal five figured humanoid hand that hands it to him. Not clear to me if it's male or female but could certainly be female.