It certainly was - the github ToS grants Github (or MS in point of fact) the ability to use your code to “improve their products and services”, and has pretty much from the get-go.

Now, with that being said, what with all the recent rulings surrounding copyright and AI, it’s possible that this clause will be deemed void in the context of training AI, but at least according to current law in the US, github was acting legally.

Whether they were acting morally is much different question, and in my opinion the answer is no - but being evil has never stopped corporate America before, or resulted in them being held accountable