An interesting (at least to me) related question is whether the Army would also make this an opportunity to change calibers - maybe 6.8SPC? Just a thought. Of course, when the Garand was adopted, the Army spec’d it out as .30-06 simply because they had so much of it in warehouses after WWI. Today, OTOH, at the rate that ammo is being used in the Mideast, that particular issue may not be a problem.
They have stated they want more operational range than the M4. That strongly infers a new caliber and while the 6.8spc isn’t bad by any means, I would prefer the 6.5Grendel.