Exactly. I don't know why people are taking such an issue with this.
If there wasn't a level of pre-preparation, the output following the reasonably sudden passing of the Queen would have been far more basic, in that they've not have suitably senior newsreaders available, not suitably dressed, without appropriate material to present. They'd have to show a blank 'holding page' or re-runs of something vaguely appropriate.
Plus without pre-recording the obituaries, they wouldn't be available for months realistically, because they're hardly going to be doorstepping the RF any time soon to ask them to sit down and talk fondly about her life are they? And as for Charles having the same hanky, WTF? Perhaps he has more than one that looks the same?
I work in emergency planning and we are constantly preparing for events that, in reality are unlikely to ever happen at the scale at which we prepare for. But we are required to have certain provisions in place and regularly rehearse them and its all useful because related smaller scale events do occasionally happen every few years. And when those event do happen, the public expect us to be ready, competent and suitably equipped to deal with the issue, keep them informed and as safe as possible.
If we'd ignored the something that is known will/could happen one day and then, when it did, flapped around not knowing what to do, without the resources to deal with the problem or provide any information, the public would be up in arms that we weren't prepared for the event (well a significant minority will still be completely over-reacting on social media but we'll just be quietly getting on wiht things regardless).
So the Queen's death is just the media's version of emergency planning so all the pre-preparation seems entirely normal to me. Their main 'day job' is reporting on world events and most of the time, they can just deal with things as they arise. But some events are of such significance, and will be so resource intensive, that it will be impossible to satisfactorily cover without doing some of the work in advance. So that's what they do. Nothing weird or sinister about it at all.