If either of alternatives #1 and #2 end up being selected, the most rational thing to do would be to terminate the I-14 designation at I-55 and consider the portion east to Alabama as simply expansion of I-20. East of there (the US 80 corridor from I-20/59 to Montgomery and anything east from there to Macon, GA) I-16 would be the most appropriate designation.
If alternative #3 is selected, then I-14 would be OK, if a little convoluted, with the multiplex with I-59 from Laurel, MS northeast to Cuba, AL. A bit out of grid on the east end (Macon-Augusta) but, considering the more egregious grid-breaking in other locales, not completely obnoxious. And with alternative #4, it would be likely that the Meridian-Montgomery corridor would retain its original I-85 extension designation (with the addition of I-14, that would be really convoluted!).
Alternative #5: if that comes about, there will likely be pressure from SE Alabama (Dothan and vicinity) to extend the corridor eastward to serve that area. East from there would be speculative: Tallahassee or Albany could constitute possible routing choices; best such speculation remain a fictional exercise for the time being.
My thoughts: It'll probably make it to Laurel, but anything beyond that may be a pipedream; the US 80 corridor, if constructed, will be as part of a separate regional concept.