Is this referring to artists opting-out (i.e. requesting to have their work removed) from the datasets used to create SD models? Because if so, I fully support that. In fact, I think artists should have to explicitly opt-in to their work being used in ML models. You don't get to violate someone's license terms and then point to an opt-out form to absolve yourself of liability, regardless of how good your intentions are or being a crowd-funded venture unconnected to any corporations with armies of lawyers.