It's probably a call back to X-Men Black where they were pretty angry at Emma for using the X-Men to get control over the Hellfire Club.
I was going to say IvX, but I think most of the current writers want to forget IvX even happened if possible.
I noticed a few things about Kitty (Kate) and Emma in this issue:
- Emma is being pretty up front about everything, she isn't lying about trusting Kate, she appears to be bringing Kate all the way into the operations of the Hellfire Trading Company!
- I think Emma and Kate were talking telepathically while Kate crossed the ocean because the beach astral plane scene seemed to imply that they were discussing this for a while.
- I think Emma has an open telepathic link with Kate so Kate can contact her whenever she wants.
- The whole time they were talking I had this funny thought that Emma is just happy that someone wants to play Hellfire Club with her at last. Like you finally found someone to play D&D with and you are super happy about it. Awe, Emma wants Kate to be her BFF!