Was Vedic Sanskrit also a ‘exclusive’ language like Classical Sanskrit? How do we know that it was called “Sanskrit”?

Sanskrit means put together, refined. Was Vedic Sanskrit also called “Sanskrit”? Because no manual change happened in Vedic Sanskrit and was natural, unlike the standardised Panini’s Classical Sanskrit.

Caste by Birth wasn’t solidified until 100 AD, so how would someone even try to make Vedic Sanskrit exclusive?

Vedic Sanskrit lead to many versions of Prakrits so it was definitely not fully exclusive.