The episode was pulled for a couple days.
The original Animaniacs is well remembered for its writing staff pulling every joke they could to see what they could sneak past the censors. The reboot appears to be doing exactly the same thing, except now in the world of Hulu and digital programming such content can be scraped once it is discovered by the public.
Case in point, episode 6 of the Animaniacs reboot was pulled from Hulu for a couple of days to edit one scene. In the episode Brain is advertising his assistance to any alien who wishes to take over the world in the form of a TV infomercial.
The show included a phone number as a gag, the number belonging to a sex hotline.
Instead of replacing the number, the episode now just features a blank space around Brain. While it may have ruffled the feathers of Hulu management, slipping a sex line number past the censors is a very Animaniacs thing to do.