To the extent that a law is unjust or otherwise morally wrong, it could be said there is a moral responsibility to disobey an unjust law (where one would otherwise be following it in a way which results in the unjust outcome). Note that GP isn't saying that it's permissible to break any law, only immoral ones.
It may be countered that the law isn't actually unjust (nor immoral), but a more convincing point is that it opens the door for companies to do whatever they like. I don't think that holds up - morality is supposed to supercede law.
It could be argued that anyone can disobey any law because anyone can find something moral or immoral - but that doesn't stand up; most people (and certainly society in general) admit some degree of objectivity in morality to the point where almost all moral questions either already have an answer, or the answer is currently being discussed (and that discussion is a process to find the right answer). People tend to say morality is "subjective" (whatever that means) or "relative", but act as though it is objective - with all the blame, shame, guilt, and assigning of responsibility. Even if it is "relative", it is relative to this society, in which GitHub operates.
Some people are interpreting this discussion on morality and law as being a matter of what a company or person does or doesn't "like" - morality is (by most accounts) a different ballgame, and should not (epistemologically speaking) be conflated with mere preference. Disobeying a just law (and doing something unjust in the process) is just as morally blameworthy as obeying an unjust law (and doing something unjust in the process). It's not a carte blanche for companies to do as they please.
I'm not commenting on this specific case; I'm silent on my moral reasoning of it, but I wanted to try and explain what I think GP was getting at.