After some back and forth last night, the dedicated thread about this issue was locked at request of OP, but this piece from Patrick Klepek just popped up on Vice:
About an hour into last night's debate, the Twitter bot @StreamerBansstarted reporting a series of high-profile accounts that'd been dispatched by Twitch, including speedrunner Trihex and the popular leftwing podcast Chapo Trap House.
Full story in the link. Attribute to Russia if old.The DMCA notice received by Twitch streamers was not from CBS, but a third-party company calling itself Praxis Political Legal. It is not uncommon for major companies to rely on outside companies to handle copyright issues for them on places like Twitch and YouTube, but it is uncommon for the companies in question to delete its internet presence.
Not long after Praxis Political issued its DMCA takedown notices, its website—still accessible through a Google cache here—vanished. The website, a sparse white page without much information, did include an email address. When VICE Games sent an email, however, it immediately bounced back because the email address had been disabled.
Praxis Political claimed to be representing CBS. CBS did not respond to my request for comment as of this writing, but Twitch's determination the claims were false answers that question.