I think these people being "real" is a secondary concern. Most readers of gossip magazines only see the characters from them only in the same magazines, or TV. Soap opears about completely imaginary characters faced a lot of success. I don't see why algorithmically generated soap operas won't have a chance, especially when adorned with "photos".
Of course I meant it as a joke. But I think the problem- or at least the point of the joke- isn't much in the fact that you haven't seen these people before. The point is rather that "gossip" is a sparse amount of information about some reality you don't have direct access to, but that exists and is consistent. So with normal gossips, it makes sense for the brain to gather all this info and try to infer a picture of the person behind it. However, if there is no real person behind the gossip the entire exercise is perfectly illusory.
Repeat a lie enough and it becomes the truth; they just have to make those fake celebs appear in TV now and then to turn them into cash cows.
I'm 100% sure in due time we'll see Elvis singing stuff that Elvis has never sung in his life; producing fake celebs would be not that different: much less initial profits but also much less royalties to pay.
No threat of lawyers, no recourse, no boring luls, no lack of luxery/perversion and punnishment patterns, which allows for envy to be disguised as moral outrage - synthetic gossip is better then the real thing.
We allready have revived and virtual stars on the stage.