T.J. Miller aka Brad Slovee on High School USA and Robbie on Gravity Falls, will be doing a Reddit AMA on April 20th @ 4 pm. Coincidentally, T.J. stars in a brand-new series for Mike Judge (Beavis and Butthead) called Silicon Valley that airs Sunday Nights on HBO and I hear is hysterical.
As for T.J.’s cartoons, I don’t think High School USA! is coming back anytime soon, but Gravity Falls is set to return this Summer for Disney Channel.