Larian's character stories are usually quite heavily driven by motivation and ambition, so since Lae'zel's entire ambition is becoming acknowledged by her Queen and becoming a kith'rak, I believe it's something that will happen in endgame by following our main character against the mindflayer struggle.
Afterall she cannot return to the Astral Plane until she earns that right through an impressive feat, so her goals will align with ours in terms of the Absolute which will cause her to earn her right to return to her Queen.
