Good observation with the robot, thank you for bringing it up
I think the robot will be used to escape the island and it'll carry the Sunny and the Straw Hats before Luffy lands his foot on Saturn, I think that's where this will be leading to. The robot would kinda mimic Momo in Wano, where instead of protecting Onigashima, it would protect the Sunny and Straw Hats
Now, whether Luffy will fight Kizaru or not is not really what I'm arguing here, if they interact more than this punch then let it be but I can't describe the precise details of what will happen to Kizaru, I think it's difficult to say anything at this point
All that I'm sure of (I may be biased, call me stubborn or whatever) is that Luffy will defeat Saturn and I don't think Oda is crazy enough to make Luffy defeat both Saturn and Kizaru in the same arc, so whether Luffy keeps fighting Kizaru or not, I think that Zoro might be the one who will finish him off but that's merely based on a mirror with Sabaody and I still find it a bit hard to believe at this point