Apparently they get a lot of notes from the network. Alex Hirsch shared one on his blog once, where the Disney suits informed him that "Grunkle Stan cannot casually exclaim 'there is no God.'"
I adore this show. The "Dipper's crush on Wendy" subplot started out as a dull cliche, but it's actually developed into the story of Dipper learning not to be a douchebag Nice Guy. This show teaches kids some pretty advanced but important stuff. Also, Rick and Morty now posses Stan's coffee mug.
I did like how this episode was the follow-up to Dipper and Mabel screwing up Time Dude's life, and they realized at the end that, animosity or no, they owed it to him to set things right. Not exactly Shakespeare, but it did say something about taking responsibility without being preachy.