Keep in mind that most people consider that growth as a bad thing.
The heyday and original intent of Trans Am was to showcase the American musclecars.
Once the smaller displacement euro and japanese imports got involved (as a "sub" class by the way) and the Musclecar era was ending, Trans Am became a different animal all together.
VTA is meant to showcase the original and most revered time in TA history.
Personally, if VTA ever decides to add on to the program, a mini chassis based sub category could be offered.
For those that like the datsun 510, 240Z, mazda, bmw 2002,etc....that would cover that base but in the meantime, VTA is a great program just the way it is.
As a suggestion, nothing is stopping you from running whatever vintage style body you want on a local level.
Keep in mind that bodies like the Mazda probably won't work well with the VTA offset tires/wheels. And NO, that rule shouldn't change just for the sake of a different body choice.
I'm in no way arguing with you but there's a right way and a wrong way to approach the issue.