Putting this also over here since there is a dedicated thread about this synoptic system now...
As expected, the 00Z EPS has decidedly trended away from a low-amplitude solution and now favours high-latitude blocking and split flow. The trough axis is also much narrower on Wednesday, despite still being negatively tilted. The trajectory of moisture return prior to the main event also looks to be less favourable than on earlier runs, hence greater CAD over portions of Dixie Alley (eastern extent of warm sector), especially AL/GA. One thing is clear: UL divergence is extremely robust on the latest run and ad verbatim the setup would imply a significant event for portions of OK/KS/MO. The main threat looks to remain north and west of Dixie Alley on the latest EPS.
The trough is a little more amplified and a little northwest on the overnight Euro ensembles, but there hasn't been a significant/major shift. GFS ensembles have been more northwest than either the Euro ensembles or Canadian ensembles though, and that can't be ignored. But to the Euro ensembles, 576dm at 500mb has been proven for decades to be a good delineator of the south/east edge of the more substantial risk of a severe weather event, and that is through northwest MS into middle TN as early as 18z Wednesday, and into northwest AL by 00z Thu. The face value dryline by 18z Wednesday is almost completely east of Oklahoma, and that doesn't account for mixing that would likely carry the dryline farther east than shown by the lower-res globals when keeping in mind the large-scale EML plume aloft that will advect out as well as the drought over the Plains. The low-level jet is also centered over the eastern 2/3 of Arkansas, through Louisiana, southeastern Missouri, and across the river into west TN/KY by 18z Wednesday, and it is centered completely east of the MS River over IL/IN/KY/TN/MS/AL by 00z Thursday.
There's been an undeniable trend in all the ensemble guidance for this to inch northwest, and if there is also any slowing trend added as we get closer, that would keep a dryline into eastern Oklahoma deeper into the afternoon. However, just using the EPS guidance you used at just face value alone, while the greatest threat is undeniably northwest of central MS and north/central AL, the threat definitely does extend (and is centered) a bit farther east than you outline as early as the afternoon and early evening, and a lower but still appreciable threat definitely extends eastward into the I-65 corridor as far east as Indiana, Kentucky, middle Tennessee, and north Alabama by the overnight. And with the wide and expansive warm sector and what would be a large-scale EML plume that would advect out overtop the warm sector (and has been modeled to do so in the operational models that have an even higher amplitude trough at times than the ensembles), this is not going to be a case where instability just goes away at sunset. This would be a situation where a threat would continue deep into the overnight hours Wednesday, if not the morning hours of Thursday before the wave pulls too far north and the low-level jet pulls away from the heart of the warm sector.
To give room for a slowing trend or wiggle room for any further northwest trend, I would say the elevated threat extends as far west as east OK, east KS, west MO, and northeast TX... but the main threat to me looks to be across the eastern half of Missouri, central and southern Illinois, and down through west Kentucky and Tennessee, through a large part of Arkansas, into northwest Mississippi, and into northern Louisiana... and then a sunset Wednesday to predawn Thursday (lower but appreciable) threat continues as far east as west/southwest Ohio, middle/east Kentucky and Tennessee, north Alabama, and maybe into central Alabama/northwest Georgia if height falls are okay enough. There will be height falls and cyclonic curvature aloft to help with large scale ascent.
There's large scale diffluence, appreciable height falls, and cyclonic curvature aloft way out ahead of the cold front/dryline out over the low-level jet axis and open warm sector. This would not be the type of threat where storms are restricted to be just ahead of the dryline/cold front. Unless there's a problem in the setup that's talked about next...
As synoptically evident as the system is on the large scale, the magnitude of this threat definitely is not still set in stone. That subtle little wave that's being modeled to run out ahead of the trough Tuesday night into Wednesday morning will have to be monitored. Those type of things can often disrupt the low-level jet and low-level convergence from where the large-scale setup would typically have it placed, and can take the convective focus away from the main upper forcing. Usually it centers it east... similar to how it does in these situations in the Southeast where we see a lead subtle wave focus the low-level jet across Georgia and into the Carolinas when the placement of the approaching main upper trough would otherwise have the low-level jet back over MS/TN/AL. If that subtle wave trends more pronounced in the data, that could not only cause LLJ/convergence displacement and disruption for the main event, but possibly cause contamination in the warm sector, and also move the convective focus away from the upper-level support. While those things may make a threat setup farther east/southeast than the synoptics would suggest, they would also likely lower the ceiling of the event as a whole. A lot to work out in the coming days...