Do you think Killua has plans to reunite with Gon? He probably can't project that far ahead at this point in time, but one of the glaring things about their separation was that there was no timeline or meet up day or place like how Gon and Killua planned to meet up with Leorio and Kurapika in Yorknew. Why do you think that is? Alluka said she'd "give Killua back" but Killua deflected the comment so it's unclear to me at least whether he is set on a reunion or not.

i don’t think “plans” is exactly the right word for this, since killua is too spontaneous to really plan anything, but i can say with full conviction that he does intend to meet up with gon at some point in the nearest future. now as to why:

killua clearly is a person that never lets go of the past and is prone to holding grudges. he will definitely want to revisit his conflict with gon, because it was far from being resolved. i’ve said it before and i’ll say it again: gon’s apology was so insufficient i can barely call it an apology. Gon didn’t specify what he was apologizing for, thus we don’t even know if he realizes what exactly he did wrong fully; he only ever told leorio that “he said some rotten things to killua” (why don’t you say that to the person you are supposed to be apologizing to, huh?). neither did killua tell gon about how much he was hurt by gon’s actions during the ca arc, brushing it off as something unimportant. 

i believe killua didn’t specify a fixed date of their reunion because he didn’t know how much time he would need to himself. i don’t think it should be a point of worry, honestly; they still have means of communication, not to mention that the inhabited world in the hxh universe was implied to be rather small, just short of making everyone run into their acquaintances all the time.

Also a follow up to an ask I just sent. what “requirements”, for lack of a better word, do you think Killua feels he needs to meet before he can let Gon travel with him and Alluka?

i assume that by ‘he’ you meant gon and not killua himself? i don’t think ‘requirements’ is a healthy way of putting it, not because of the meaning, but because both killua and gon need to work on their relationship and their respective issues. killua played his role in their falling out, too, and he should reconsider the ways he expresses both positive and negative emotions, just as gon should mull over his self-destructive tendencies and self-centered attitude, before they can start rebuilding their relationship with a healthier approach.