In my opinion, is appropriate to have some kind of period of mourning with such a historically significant moment and changing of the guard
But it's a shame to totally cancel things that bring people joy for a long period of time.
UK often experiences tragedies in which many people day in much worse circumstances than this, genuine tragedies, and there is no such postponements, life just goes on. Strange here to react in such a strong manner if they put 10 days with no sports and other activities.
Not to say that this is not sad