We are observing a live example in the OP right now. If you are an artist working in some specific style, then even a small dataset (just 30 images in the OP) will render future works much less desired. Of course big companies have compliance rules, reputation and so on, so they won't use "gray" art in the production. But the is definitely not enough bigcorp contracts for every artist, so smaller less known ones would compete basically with themselves. Imagine someone choosing between paying for original art X thousands of dollars, or generating 80% similar in quality art for "free".

PS: after posting my comment above I've realised that by idea won't work. Art will become public sooner or later, just scan physical medium, or rip drm off the digital one and you will get the dataset for NN generator. Well, it will be a huge mess. We will see how it will turn out.