Connie Britton has left this show
From what I understand, something happens to her character in the latest episode which is not good at all. That's all I'll say for now as I don't want to spoil anything being that the episode is currently airing at this time.
Also heard online that it was Connie's decision to leave. Moreover, her decision seemed to be politically motivated as well considering the fact that she was unhappy with how Nashville stands at a political level. Seems like a stuck up and stupid reason to me.
With that being said, I just can't see this show surviving much longer without Britton being that she's the frontrunner of this show. At this point, they might as well just end it at Season 5 and be done with it for good.