If every state except two in a supposedly democratic body made and controlled entirely by said states is of the opinion that something is illegal according to that body’s own laws, and have voted upon such language every year consecutively and similarly unanimously for decades… then is it not? And if not, does it matter?
Again though the UN could enthusiastically support it and it would still be every bit inexcusable. There is no further value to discussing whether it is “legal” or not.