So I started looking into this. Since 2015, this line has been ***government-owned*** -- by the North Central Mississippi Regional Railroad Authority, an agency owned by seven counties, with financial support in grants from the state and federal departments of transportation. (This authority was formed by the North Central Mississippi Rail Coalition.) The line is currently leased to / operated by RailUSA. The Authority has $30 million of bonds to pay off from buying the line and is drumming up business.
The line is currently being upgraded so it's all ready to handle 286,000-pound GRL. Track is being upgraded to Class II.
This does raise the question for me of whether the line might eventually host passenger service again. It's in government hands, which means a friendly operator. The bridge replacement is the *really* expensive part of upgrading, and with new bridges good for 286,000 pounds, they'll probably be good for passenger service. So it would "merely" be track and signal work, plus stations.
There's no significant intermediate population on either route, so it's just a matter of what's faster, or which cities want to put more money into stations. That could change again, as it has before.