In the campaign, Master Chief promises Cortana that he will bring her back to Halsey so she will fix her. Cortana replies saying don’t make a girl a promise you can’t keep. Master Chief always keeps his promise so i think that Cortana is definitely coming back in Halo 5. Also, I don’t think that the Didact would be killed off so easily, so he might make a return as well. I remember 343 industries said that Halo 4 will have a cliffhanger, but i don’t seem to see what unanswered questions there still are. Could you maybe name some?
Don’t put a spoiler in the title idiot