You're assuming people would still insta pick early game counters even if they can have elite infantry + premium tank + calliope?
Ofcourse, almost nothing changed since usf rework and commander revamp when it comes to usf vs okw early game EXCEPT new commanders with strong early call in units. If you choose to play, lets say, heavy cav you still have the same bad early game matchup against okw which puts you behind when you reach mid and late game. Thats why most people switched from instalocking heavy cav to things like mechanized or armor. These doctrines are pretty much the only "fix" usf got in terms of their viability against okw early game dominance.
Now look at this commander. We have rifle nades for REs which are cool but in no way help you defend against volks blob, its more of a supporting tool. Next, 2 abilities copied from heavy cav, pretty good but in no way help you survive early game, and there is good chance you will have your full infantry roster at 3cp so rangers might be not needed this late. Then there is dozer blade, no comment... And last, calliope, which one of these units can turn game around in your opinion, pershing or calliope? I think its clear.
If you change dozer blade with easy8 you get more variety in terms of armor, but not raw strenght increase. When you tech to tier3, which you should do as soon as possible with this commander, you will probably want 75mm to deal with vetted volks and obers. Next vehicle you will want is probably jackson to deal with panzer4s and very possible at that point panther. There is little room for easy8, its not good enough to be obvious pick over 75mm and has some serious drawbacks (low mobility, slow reload, not so great survivability).
But the most importand reason why easy8 wouldnt be broken here is that ITS NOT A CALL IN UNIT. Its the meta for some time now, even if you look at the previous team tournament (the one with 5k$ prize) you can see that doctrines with call ins are prefered even in team games, armored assault every game is good example. When it comes to 1v1 its even worse, its all about command panther, is2, kv2, command p4, tiger. USF is forced to go armor or mechanized vs okw but pershing is still good vs ost becasue you dont get murdered in early game and you get precious call in vehicle. Easy8, being somewhere around okw p4 and t34/85, requiring tech is simply no match for these strategies, at least not alone. Now compare fuel cost to deploy stuka + c panthers vs calliope + easy8. Which one of these combinations is stronger? Which one is cheaper? Remember, no need for tier3 for okw. In realistic 1v1 scenario spec ops is still much stronger doctrine.
And please stop calling easy8 "premium tank", its as premium as okw p4 or t34/85, and nobody calls them premium for some reason.