If you didn't know, MTV announced earlier this week it would be adding a revamped version of the classic, with an all-new cast, to the network's upcoming programming -- a cast in the age range of the OG "Jersey Shore" stars when they started out way back in the day.

Clearly, that didn't sit well with The Situation, Snooki, JWoww, DJ Pauly D, Vinny, Deena or Angelina ... who all posted the same statement slamming the new show, saying, "... we are not in support of a version that will exploit our original show, our hard work and authenticity to gain viewers."

We've spoken to high-level sources at MTV who say show and network honchos were not only blindsided ... they're PISSED, calling the cast "ungrateful" and saying, "It's disgusting they'd take a swipe at the network."

Not only that ... they say the cast's claim MTV was struggling before airing "JS" just isn't true, and was an uncalled-for low blow.

We should mention ... the OG cast isn't going anywhere, at least not yet, and their "Jersey Shore Family Vacation" still has a home on the network.

Can't say the cast never had a shortage of drama ... and here's more proof.