Perhaps a better question would be: In either case, what will the impact be on the civilian market if either of these are adapted?
For example, can we expect a short, handy Remington model 7 in either caliber for youth and women shooters who are averse to the recoil of the 7-08, etc? Or, will there be lots and lots of surplus 5.56mm and/or 7.62mm ammo at bargain prices for those of us who just want to shoot a lot?
Two well known bolt action rifle manufacturers have expressed interest in offering regular production 6.5 Grendel bolt action rifles.
The availability of low cost surplus ammo of the 5.56 and 7.62 has to do with NATO adoption and manufacture on a global scale. Adoption of a new cartridge by NATO is not a short process and is very political. Reaching the level of bargin prices would take years to realize as it did for both the 5.56 NATO and 7.62 NATO.