On political matters, the Queen is the servant of Parliament, unless exercising the reserve powers which would only be done to address a constitutional crisis.
The article is also, in my view, misrepresenting the speech which does not, in fact, refer to sexuality even once. It refers to racial discrimination, sex discrimination, skin colour, religion, and political beliefs explicitly. It does mention sexuality at all.
” It would be unconstitutional for her not to do so.”
LOL. Then the monarchy has clearly outlived its usefulness. The queen will suposedly use socialist code words like “gender equality” and “women empowerment”. Everyone knows what she’s talking about and I doubt that this is all a consensus in the “commonwealth”.