This is great! As said by the others this is an excellent addition to keep track of model versions, particularly when you are finetuning your own. Now we can use commit messages to keep track of all model’s changes, too.
Thinking about how this will work once people start using it, I’d like to raise two possible concerns. It seems that you can clone other people’s models because they are all public anyway. That is great, but possible concerns are:

Will the branching be visually clear? In other words, will it be clear to users which is the original repo?
In the search results, the original repo (or most downloaded repo?) should be shown at the top in case of forks, or at least there should be some clarity here. (Imagine that everyone clones bert-base to play with it or to finetune it, and suddenly there are hundreds of bert-bases.)


Because of this possible increase in duplication, it might also be fruitful to bring back the discussion about required fields in model cards. I don’t know if that has been addressed yet, but perhaps this is a good time to introduce required fields like license and training data used. I’m aware that that’s not what this PR is about, but it seems related enough.