During Messiah Complex, they spent their time talking about her importance instead of her origins. Afterward, Hope's birth mother (because I still consider Hope Sr. her real mom) and origins were simply never brought up again. It wasn't a mystery; it just wasn't mentioned. Then when when Reed Richards asked about Hope's family, Hope & Anna were the only X-Men in the room, and they simply didn't know. So when Hope told Scott she wanted to find her birth parents, even though he found out already off-panel, he decided to let her find out for herself.
I'm glad Hope has a real parent and isn't just some fragment made by Jean Grey or experiment made by Sinister that somehow ended up in a hospital.
At this time, I'd like to do my "I told you all Hope wasn't Jean" dance.