I think I've figured out the reason behind the lack of Carl in 6B. Carl is dead. I'm not being over dramatic. Just here me out. My theory is that after Carl is shot in 6x09, he actually ends up dying. Think about it. All his interaction so far is just a hallucination from the people that loved him most. Let's breakdown his scenes: Carl is healed and we get a blissful scene of a happy Grimes 2.0. Carl and Enid roam the forest and behave like kids. Carl leads Walker Deanna towards Spencer who ends up getting closure after his mother’s death. Carl declares that Michonne is family. Carl catches Jesus. Carl holds a baby Judith while Rick leaves for Hilltop. 6x10 is the episode that features Carl prominently since it is the aftermath of 6x09. The episode opens with the best case scenario: Carl is healed. Except this is a hallucination invented by Rick. As we all know, this isn't the first time Rick conjured up a ghost. In fact, this hallucination doesn't just stop with Rick. Michonne, too is in on it. Just like Rick, Michonne sees dead people, and the loss of Carl who essentially became her son renders her in this grief. Rick and her concoct this happy, blissful image of what could have been. Enid too has hallucinations of Carl. Enid had grown close to Carl during their time in Alexandria, and the two would spend their time in the forest. All of Carl’s interaction are with the people he has had profound influence on. I posit that by the end of the season, we will get a quasi The Sixth Sense reveal of Carl as a ghost. But I know what the naysayers are about to say. What about Jesus? He’s never met Carl. Why would he hallucinate a stranger? Friend, you’re telling me that Carl’s only interaction with a non family or friend is with a guy named Jesus. I’m gonna let you figure that one out. I rest my case.