"Rebellious Scots to crush" came from the 6th verse of the British national anthem. It mentioned Marshall Wade and was therefore obviously about the 1745 Jocobite uprising, not about William Wallace (portrayed by Mel Gibson on film). Please amend your belittlement accordingly, lest you appear uneducated.
Does that suffice?
I thought I had heard something about it being removed but I couldn't find anything. The only thing I could find was that it had been looked at about a decade ago but they decided to leave it alone. According to that piece, it looked like Parliament would have the say on whether it was changed, not Buck House, so I don't know how "official" that editing of the lyrics is. On the other hand, this says there is "no authorised version of the National Anthem as the words are a matter of tradition", so who knows.