Unfortunately some of the comments in this thread I think are close to falling under rule 4 of this forum.
“The entire spectacle of the jubilee is an exercise in the British people humbling themselves before the queen”
Shows a misunderstanding of the person and office of the UK’s head of state, which leads I think to presumptions about the use of the term that may not be correct. It may not be meant, but it reads as an irrelevant stab at that political system.
“I happened to be born to the right parents and all I did was what it seemed like I had to do at the time. None of this is due to any great effort on my part and I just happened to live long enough to get this far. Now I’m getting all this honour dumped on me.”
As opposed to “lying, buying and cheating my way into this top job”, which of course is also close to breaking rule 4 but is intended as an example and I am not indicating which country I am aiming at.
“…and especially not for She Who Has Everything but a Family Name.”
I did not realize that contributors to this forum has such close relationships to, and knowledge of the sentiments of, the UK Royal Family ;-)
Back to the subject. I think this is an example of a shift in meaning, but not a complete reversal. Whether a heartfelt emotion or a comment deemed to be expedient, I read it as recognition that the support and size of the celebration is for the office and position that she is in, not for the single human.
Not saying this is true, but that is the sense intended. A “relative humbling”, not a parallel with Uriah Heep’s usage…