I don't think it will be sage mode, her byakugou was maybe what we saw her use against madara because its freaking madara!! She would have to consider keeping herself alive if she was going to fight afterall she still considers a medic having to be the last to die.
So maybe she has other techniques personally I am not expecting anything big because comeon we can't set the bar higher for Sakura to surpass lol i would like to see some range jutsu from her its the only thing that makes her rank among the fans average.