Polls showed Hillary winning those states in 2008. In 2004 she'd probably have been able to win Arkansas, if she ran a good campaign and won the election she could probably have won most of them. The pre-Obama admin Hillary had a significantly different coalition and her showing in 2016, in those special circumstances, shouldn't be taken to mean she would always have been a bad fit for those states no matter when she was the nominee (however it could be taken to mean she's a bad candidate overall and so while she may do better in those states it's possible she still loses them and the presidency, with the probable exception of Arkansas.)
I am assuming you mean that the pre-Obama admin Hillary coalition was more working class and less educated. A lot of the original Hillary '08 coalition voted for Trump in 2016 and 2020.
