Small potatoes e-celebs would probably have to prove that Fatrick's Supertips voices are causing harm.
It isn't solely celebrities. The right protects individuals from having their image commercially exploited without their consent, regardless of whether they intended to exploit it themselves. Even in the most important case involving an actual celebrity,
Waits v. Frito-Lay, Inc., Waits didn't allege he was deprived of income by someone making money off his image.
In fact, he argued he explicitly did not want his likeness (in this case his voice) commercially exploited at all on principle, and that part of his core reputation was that he rejected such crass behavior as doing commercials.
The right also implicates privacy and reputation. A case that isn't U.S. but presents a similar issue is the TechnoViking case. You might recall this old meme:
The Viking himself comes in at about a minute in.
Is it an infringement just to have the video? Pretty obviously not, it's been up 14 years.
However, the original filmer started commercially exploiting it, selling merch, and similar things. TechnoViking sued and bankrupted the guy.
I'd argue using people's AI voices to collect "donations" is commercial exploitation of their image and falls well within the ground covered by the cause of action.
I'll note right of publicity (and the other rights sometimes named differently in different states) may look like an intellectual property right, but it isn't. The economic end of it looks like an IP right, but it also covers privacy, reputational and other dignitary rights. It isn't really a single clear-cut right so much as a bundle of intertwined rights, and violating even one can establish a right to relief.
Using a replica of someone's own voice to defame them certainly implicates dignitary interests.
Throw in that most of the people who would object to Pedomelton's exploitation of their likenesses are in competition for the same superchat/tip money and you have a bunch of other cool business torts.
tl;dr something could pass muster under "fair use" if you were just talking copyright, yet still violate other reputational rights.