User blog comment:Thailog/Ep. 206 "Bloodlines" discussion/@comment-5060912-20120603023636/@comment-432124-20120603033311

Not if the Legion of Super-Heroes shows up and the Team members do it with a Legion ring or some other time machine that the Legion has. And yes, that would be possible if some Legionnaires had gone back to the past for a mission before returning to their time and finding it changed into Bart's post-apocalyptic future.