IIRC, the general rationale behind the 451 RFC was that this provides a means for a third party to communicate that they are censoring the content, presumably b

IIRC, the general rationale behind the 451 RFC was that this provides a means for a third party to communicate that they are censoring the content, presumably begrudgingly. So, in the case at hand, GitHub is using 451 to communicate that a government censor has required that they take some content down, not that the company itself has decided to remove the data of its own volition.