It's possible, but in a world where copies and imitations are cheap, authenticity becomes more valuable. Would Charli XCX's brand and image benefit from having a shallow AI clone out in the world? In most cases today, when streamers introduce bots, they give them a separate on-theme identity. I'd be willing to bet that creators would gravitate more towards that approach with these AI characters as well.

Of course, that character (or can we still just call it a bot) could still shill promotional content...

I run two (extremely simple, just a few paragraphs of system prompt) AI bots in two streams I mod. One is a plushie penis, the other a sentient food truck. Viewers like them ;)

Yeah building up on or more "sidekick" type personas seems like an approach that could be very successful if executed well, and reduced potential for backlash that impersonation the real person.