My only problem with that theory is everyone was saying the first time they showed Morgan that he would definitely be in the finale to help rick and his crew fend of the governor. Ship sailed on that theory last night...
I think the story might be closed on Morgan. It showed the contrast between rick/morgan character by showing how the family kept rick from teetering off into la la land like morgan. He lost his family, rick saw that and was able to stay somewhat in one piece.
Plus how could morgan be any healthier after all that time passed? They were in the prison for a while and morgan was completely sliding down hill no matter what rick could do, how/why would morgan turn around now?
Although maybe that is how rick and carl make it through the first couple episodes by heading to morgans shanty town and recuperating...I guess anything is possible