It isn't against the EULA since it doesn't provide anyone with an explicit advantage and simply only provides players with vanity items.
It's no different to other large servers allowing people to buy their versions of cubelets.
It really wouldn't be against the EULA because you're pretty much buying cosmetics. :p
But as said, you're meant to earn the Cubelets through gameplay. :]
Okay so if it isn't against Eula okeh...
It's just vanity so no In-game advantage...
But think about this,
Everyone knows the Loot Cages in Overwatch or CS:GO
They're like very rare to get unless you buy them..
That's basically the same thing that will happen with Cubelets...
People without vanity Points will have to grind them,
And people with Iron+ Rank should then easily be able to buy them...
Well it's like every 'Big' network but does Cube need to be like every 'Big' network?
Not really...
Also
Then the purpose of Cubelets will basically be gone...
(The purpose of Cubelets are to Reward players after the 'Hard' work that they spent winning 1 Game...)
Well what can I say really I have 50+ Cubelets....
lel....