They subverted the tropes everyone had taken for granted since the 50's or so that TV was expected to have. They outraged parents and the extreme conservative groups that wielded fairly significant power at the time.
Shortly before that we had 'the Dungeons and Dragons' scares and it was the time of the violent video game and explicit music crackdowns. Those cartoons became targets for those same kinds of people.
Without those shows, we probably wouldn't have the kinds of cartoons we have today.
I would definitely include more than just the two cartoons in the article and MTV as the sole disruptors of cable.
But, the cartoons of that era were definitely disruptive in a way that's hard to appreciate without experiencing.