I kinda hope that the critical events which set the foreshadowed future in motion occur during the next chapter: something big happens to the both of them as Kawaki's will and Konoha's ruin are not something which come about on an off-day when you're a little bored. I think they should (and hopefully will) kill off Himawari simply because that event would have fundamental and long-lasting effects on the characters. It would also be the first sign that Boruto's entire world will eventually be destroyed.
As for the chapter itself Delta will either a) win the fight, b) tie with Naruto c) not fight him d) lose but only after a devastating fight (pyrrhic victory for Naruto) e) escape or e) be captured and escape. Having her be curb-stomped by him will paint Kara in a bad light as they need to secure their place as a dangerous threat in the reader's psyche (especially if they are to be the main villains). Remember the Akatsuki who from the first moment they appeared in the original series were an intimidating force which even the most powerful ninja were unlikely to beat (it was only after the battle against Kakuzu did the tables slowly begin to turn). By having Delta go in and be swat like a bug it will tar the rest of Kara with the same brush. It doesn't matter if KK or Jigen are tough: by that point we would have had two years or so to internalise the fact that Naruto can defeat them with ease.