People have asked about how they were able to call John and what their cell carrier was... Well here you go. I wanted to have a cute call back to the aliens in this arc and it gave a way to push Lyn forward too. They aliens had thought that John had just vanished, along with his implant... but when George entered the afterlife with his cellphone too, remember nobody has technically died to get where they are so they all brought physical objects with them... the alien device started broadcasting which gave them the ability to contact each other. Suspend your disbelief... it's aliens and dimensions folks. And no, there's no clone John. That's still just an April Fool's gag...