Beavis and Butthead was an unusual tv program for its time some years ago because it used unappealing animated characters saying things that were harsh and expressing themselves in curse words. That set the tone for many cultural and political situations being critiqued openly through the mouths of other such animations as the years went on.
Before Family Guy or Bob's Burgers, there was Beavis and Butthead. Beavis and Butthead was absoltuely the pioneering show for controversial animated programs. There is no doubt that B&B came first before every other show that was ever considered controversial while being animated. Therefore, it holds cultural significance these days.
No, I don't actually think that Beavis and Butthead was apioneering show for controversial animated programs. This was a time in American entertainment when cable was starting to branch out from reruns and old movies. It was also a time when animation was starting to get edgier. B&B were simply riding the wave of that trend.
No, this show did not act as the first show to kick off adult animated programs. If you look at the very controversial show Family Guy, it has been playing on television since the nineteen eighties, which I believe is before this show had even started, so it was not the pioneer.
I do not believe Beavis and Butthead was the pioneering show for controversial animated programs. There were plenty of other animated programs on before this one debuted and it had a very niche following. I don't think its survived time very well either so you haven't seen it particuarly influence anything since then either. Thankfully.