Jeff DeMunn asked to leave, so Andrea had to take Dale's place and unfortunately take the same death (At least that's the "glass half full" way of looking at it, it's much more likely that AMC just wanted her gone). So, now somebody has to take Andrea's place. I personally think Carol has the most reason to. If not her, I could see Beth being gradually molded into her. Carol's already pretty close at this point though.