It's not an unreasonable question to ask regarding the preparation that the X-men gave Hope. However, I think part of this was actually addressed shortly after Second Coming. I remember writers like Kieron Gillen stating that the X-men avoided talking about the Phoenix because Hope had just lost Cable and was in a vulnerable position. Then the events of Schism took place and that definitely disrupted everything. Plus, we don't know how much time had passed or how much Cable knew about the Phoenix. From the looks of it, he didn't know the full story until the events of X-Sanction. In that sense I don't think it's right to criticize the preparation or lack thereof for Hope. It seemed nobody had a full understanding of what was going on until the events of Avengers vs. X-men drew near. That's not to say they couldn't have done better, but hindsight being 20/20 I don't think we can put too much weight on Cyclops or the X-men for how it panned out.