As much as I enjoyed AoA, I don't want to go back to it. I want to see Loki continue to grow and develop and show more facets. I don't want writers to dismiss what growth there was before, and yeah, if they bring back aspects or use elements of his earlier series, great! But I don't want a direct continuation from AoA, as there has been development, and growth that should move forward and not go backwards. All these aspects are a part of his character and that just make him more complex and add more depth to be explored.
And I agree, unexpected is good, and Loki gives writers a chance to do so with his character, but yes, there are limits. Throwing a cape on him (just an example) and saying he is a full fledged hero, wouldn't work as readers would be expecting some behind the scenes plan, by him. So writers can do unexpected things, but it would still have to connect with his character traits, personality, and past experiences. So yes there's definitely limits, but also lots of possibilities, too!