Well, I read the whole article and while it is well written and I am fairly well versed in reading legal text... I still do not know the answers to these questions:
What is the law concerning ‘Open Carry’ of a gun in Mississippi?
What is the law concerning ‘Concealed Carry of a gun in Mississippi’...
The article discusses the semantics of the ruling and associated background material - but does not state what the law is in understandable terms — not that I could find.
Open carry is now legal, as long as the gun or holster is visible by ordinary observation.
Concealed carry has not been changed, except that now you do not have to worry about your gun being exposed, at least not in a legal sense.