Settle down, people. The way it is worded in the final screen heavily implies that Kenny is, in fact, dead. It says he was "lost to the herd". By saying "lost to", as opposed to "lost in", it suggests that Kenny was killed by the walkers massing around him. "Lost to" is used to mean "died as a result of". If everyone wants to contest his death, then I would recommend "presumed dead", because his death is heavily implied, and his survival is extremely unlikely. Especially in the scenario with Ben, as he was surrounded in a tiny passage by walkers. Admittedly, his survival in Christa's scenario is far more likely, but only because we cannot truly be sure how many walkers were in there. Only a few walk past the hole after Christa is saved. They could be all that was in there, there could be many, many more. But, regardless, it's heavily implied that Kenny was killed by the walkers, and the likelihood is that he was killed.