Twitch Updated their Sexual Content Policy:
- Changes: Certain content now allowed with labels
- Artistic Nudity: Permitted under Sexual Themes Label
- Game Nudity: Contextual; labels necessary
- Body Painting: Acceptable with appropriate label
- Mature Games: Label generally covers content
- Stream Visibility: Impacted by content labels
Twerking, grinding and pole dancing are now allowed without a label.
The thing is, teens with accounts set to 18+ do access twitch. And they are going to be diverted there more and more which can draw viewers away from genuine streamers who are just gaming.