Might as well post this, seeing as I’ve used it in a few threads.
[Image Description: an oil painting depiction of a toad dressed in gentlemanly Victorian period clothing with a caption that reads “gentlemen, it is with great pleasure that I inform you my name was included on the tesseract block list”]
The author of the code always has the rights to do anything they want with it (except take other people's code and put it in there). The license grants rights under certain conditions to other people.
So this might only be complicated if someone else contributed to the repo, but I doubt it that removing or rebasing someone's contributions can ever be judged illegal.