I hope Kizaru faces as many opponents as possible but I think G5 would be last cause I don't see him overwhelming him and facing others simultaneously. We'll probably get Nika nika awakening contrasted with Logia awakening with further exposition from Vegapunk.
As for prior to facing Luffy, clashing with Zoro would be nice and hopefully with more of the Straw Hats. Luffy's kinda busy looking for Bonney so Oda could go the route of Kizaru first stopping to assess the situation outside the labs with CP0, Straw Hats, punks and Seraphims or go directly inside to deal with Luffy.
Regardless I think Oda will treat Kizaru well, I just don't think losing or getting overwhelmed by Luffy constitutes bad treatment or anything.