Kitty 'breaking bad' is a great storytelling idea, but any impact of her sudden acts of violence is undercut by .... solicits and other comics.
Her channeling rage over Jean and Bobby's murder is undercut by the knowledge that they will be alive shortly. So the reader already feels that this superhero resorting to murder, is not entirely justified. Imagine if the Punisher's origin story was undercut by solicits months beforehand that the Punisher's family will be starring in a new solo series.
Furthermore, you have an Iceman issue debuting the same week as this reveal. If you thought the killing of Ms. Marvel but announcing her new status quo in a few weeks was bad, here we don't even have time to reflect on Kitty becoming the Punisher over Bobby's death before we are already off on an adventure with a joking, flirty Iceman.