Does the 6.5 grendel have the potential to replace the 5.56 for the military?

[Squatchy]

If not the grendel then maybe another 6mm/6.5 variant? Bullet design and cartridges have improved greatly since the introduction of the 5.56x45 about 70 years ago and only continue to get better in terms of terminal ballistics. If you had to take a guess what would your prediction of the next standard nato caliber be?