Much of the discussion upthread has focused on the Atlanta end of this proposal whereas most of the push seems to be from the Dallas/I-20 corridor end. There is also the question of where a route > 750miles (which a discrete Dallas-Atlanta route would be) fits in the PRIIA scheme of things.
If passenger service Meridian-Jackson is contemplated, and since CONO passes through Jackson, then what about routing Crescent through Jackson, where any meeting or joining/splitting for Texas could then take place? It would also bring Crescent into Baton Rouge's catchment, via the stop at Hammond. Running time would be longer of course, but if there were affordable ways of getting Jackson-New Orleans running speeds more competitive with driving times and drive down total Meridian-NOL times, that would benefit CONO also. The question is then whether the Southern Rail Commission would have a problem with the bypassed communities like Hattiesburg.
If Texas, Louisiana and Mississippi cooperated on a PRIIA service using Superliners over the existing TE route (so reinforcing those catchments) and onward to Shreveport, Ruston, Monroe Jackson and possibly Meridian, then that creates economies of scale at Fort Worth Amtrak maintenance since it will now have two based and one passing Superliner routes.