Wow, talk about a mean-looking piece of hardware! Maybe the Abrams needs a comparable update?
I don't see the point, yet.
First, we have to see this gun actually installed in a fully operational tank.
Second, we should wait to see the actual rate of fire of such gun, the storage capacity within the Armata due to the larger ammo, and the expected life of the gun.
Only then we can have a real idea about its performance and eventual advantages over the current Russian 125mm gun or Western 120mm ones.
Last but not least, in a tank-to-tank fight the main ammo involved should be APFSDS, meaning a sub-caliber ammunition. If we take a look at live firing experience, this ammo effectivity does not rely on the gun bore caliber but on the chamber size since what defines the projectile velocity -and its armor penetration- is the propellant volume.
I doubt that a significantly bigger gun breech, and thus a gun chamber, can be easily accomodated inside a small turret like the Armata one without affecting the ammo carroussel performance.
Yet to be seen