>>30126569nta, but yes, they literally "control" all the talents' official channels and social media accounts, which are corpo-created and the company has supervisor access privileges, and the talents basically just have subordinate guest access.
If you think about this longer than two seconds, it even makes sense. The talents ultimately just play "characters", which are created and owned by Cover in the legal sense (for example, a talent may leave the company or do other side-gigs, but she can't take the character skin and name with her, which belong to Cover). Retaining final control of the characters' accounts and channels is basically just proper insurance. 99% of the time you won't need it - the talents stay in line, just log on to play their games or make their inane inoffensive tweets and everything goes smoothly - but in the rare cases where a talent might go rogue and does something that goes counter the company line, it's good to have ultimate access reserved so you can for example terminate a stream, delete a tweet (or hell, even put out a company-written tweet in the name of the talent), and shut out the talent from accessing their channels/account and do more harm.