In Werewolves of Highland, the hobo's voice is almost identical to that of Spongy, a hobo character on Mike Judge's other show, King of the Hill (1997).
Returning classic characters include Coach Buzzcut (although his gym attire no longer has the word "coach" written on it, Stewart Stevenson (surprisingly STILL in a Winger shirt), David Van Drissen, and classmates Dean Zunker and Cassandra (although the two of them have no dialogue).
First new Beavis and Butt-Head in 14 years. The last proper segment made was Beavis and Butt-head Are Dead (1997) back in 1997 (although the characters have made a few "one shot" appearances in many miscellaneous situations/settings/etc. since then).
First time Beavis and Butt-Head make fun of reality television (although they still make fun of music videos as well).
In Crying, the lunch lady seen in the background resembles the obese woman in the older seasons who was portrayed as both a school bus driver and a phone sex operator.