Perhaps I'm an outlier, but generally the value I derive from art is not from its backstory. I love a Bach fugue not because he was suffering, content, had many children, or whatever else, but because it's an extraordinary composition. I'd feel the same about AI generated art.
We view forgetting as drift in the model's predictions on old data. So the fix is simple: use a KL penalty on past (pretraining) data to keep old outputs fixed while the model fits the new data. 2/8