What’s different about AI? People are cheap. Anyone who wants to do this can already do it just with mechanical Turk or just hiring writers in low income countries.
Amoral, not immoral. I mean the AI won't make any moral judgement itself, and using it for whatever task doesn't carry additional moral implications other than those of the task itself, opposite to humans in which you have to care at least a little bit about what you're telling them to do.
About the task itself, it may be immoral by nature, and now it can be executed orders of magnitude faster and without the moral concerns concerting the workers themselves.