Exactly! It's not sufficient but it's at least necessary. Today we have no proof whatsoever about what code and data were used, even if everything were open so

Exactly! It's not sufficient but it's at least necessary. Today we have no proof whatsoever about what code and data were used, even if everything were open sourced, as there are reproducibility issues. There are ways with secure hardware to have at least traceability, but not transparency. This would help at least to know what was used to create a model, and can be inspected a priori / a posteriori