Style isn't protected by copyright. Maybe there's an argument that it should be, but right now that's not a protection which exists. Training is neither public

Style isn't protected by copyright. Maybe there's an argument that it should be, but right now that's not a protection which exists. Training is neither publication nor distribution, so copyright is entirely out of scope at that step. Again, maybe there's a moral argument for some sort of control, but copyright is completely the wrong framework to think about it in.