I agree with the point you made elsewhere that releasing the data is irrelevant.
You demonstrably don’t understand what it means to open source an AI model. The code is not relevant at all, the same code will not produce the same model weights, it is not deterministic.
Also you will need millions of dollars to retrain, retraining is not the goal. The model weights are the source that was opened.
Model weights are not "the preferred form in which a programmer would modify the program" but more like "the output of a preprocessor or translator" [0], and thus are not "source code", but viewed as code, are more like object code. The training data, training configuration, and program source for the training routines are "source code", without which the model as a whole is not truly open source, just as much as the program source for the inference routines are.
[0] for the relevance of the quoted material to whether or not your description meets the Open Source Definition, see the definition itself: https://opensource.org/osd/
It's source available, but it's not "open source" in the historical usage by programmers. Microsoft could not take their model weights and use it. It's not open source.