To be more accurate, the channels were ran by fans but given the "okay" by Cover to call themselves "official", here's a long
write-up about it. Obviously all of this went out of the window after Cover abandoned China, the channels went rogue and eventually abandoned. What I'm trying to say is that some of those "fans" may still have access to the account and can do whatever with it.
Anyway, I compared the latest video to the
last one uploaded years ago. The latest one seems "lower effort", there are no JP subtitles, and the video description is also shorter (older videos include link to all the past videos). Basically, I'm still skeptical if this has anything to do with Cover.