After finally getting William back, Oliver sees to it that Samantha and their son get themselves far away from Star City, and don't tell anyone - including him - where they're going. It certainly makes sense, and despite limited involvement with either William or Samantha, Stephen Amell does a good job of selling the emotional weight of this decision. Are they really gone for good though? The show has introduced them, and made a big drama out of their being a part of Oliver's lives. While the decision to remove them permanently makes sense from Oliver's point of view, and means we don't have to deal with Oliver-as-parent, it's also going to leave the questions about a potential return hanging over the series until they do finally come back, or something happens that definitively rules them out from returning.