I think if any of the options in the current GR except Aigars's (and maybe
Sam's?) passes, that would effectively be a change in our current policy,
even if the current policy is not precisely intentional.
IMHO my option will also be a change in our current policy, but, instead of requiring the training data itself, my option would just require adding a documentation section describing how to create/gather and process data required to train such models *if* someone would want to reproduce them.
I expect that any policy change would need a transition period to be practical.