9.1 makes it pretty clear she can bypass the Arbiter due to her link with the Winter Queen: after that quest, Primus confirms the two sisters connect the "Lifelands" and the Shadowlands in a special way.
If Arbiter was awake they likely would've gone to Ardenweald as natural spirits go there anyway. If Arbiter was asleep they would've went to the Maw. We don't know how Wisps work (not even the Brokers do) so unsure as to what would've happened if Elune made them into wisps into of sending them to SL... but to her it was more important to send them to help Ardenweald than it was to rezz them back into being ghost orb warriors. (Even though some of them do that in the Battle for Teldrassil)