My point is the arena would be popular because it would employ more popular maps that would ease the pressure on the late war orange sydrome. I
No it would not.
How do I know that? Because when Ndisles or Ozkansas are up in Blue, it's still the same as if it would be any other map - 90% of players are in Orange until arena caps go into effect. And even after that there is no difference in distribution of player numbers between Orange and Blue compared to days when those two maps are not up.
If it doesn't change player behaviour now, how should it work when there's an additional 3rd arena?
BTW, TT isn't really Tank Town anymore. TT concept died 2 years ago. A few guys still tanking on NDisles, but it's only a shadow of it's past. And do you even know that the Tank Town area on Trinity was once the busiest part of the map, with a hundred players & more? Now it's completely empty...