The article distinctly identifies the Queen as the one who made all of these ceremonial decisions that were respectful of the US.
Don’t confuse the Queen with the UK politicians.
I understand she takes actions when she is “advised” to do things under her authority that were actually decided by others to whom the Crown’s authority has long been delegated at this point, but she is still more than just a figurehead and make decisions like this.
Her Majesty can stop this nonsense anytime she wants to. That’s the point of a constitutional monarchy. She is no mere figurehead as a recent PM discovered when an admiral stated that his oath is to the Queen.
If she stood up against Marxism the military and the people would stand with her.