Not wanting to wish for or hope or anticipate for the worst... just to make that clear.
But is the Prime Minister one of the select state figures where News outlets would have an obit package in the can for them? I would have thought they would be given the increased risk for events such as assassinations etc.
News organisations have obit packages/articles ready for most important people, and those who are well known but not particularly important. It's not a few select people who they prepare for as has been seen many times when a celebrity dies and there's a package on screen within minutes.
However the Prime Minister is one of those whom the broadcasters, particularly the BBC have procedures for, and are rehearsed for. Not just coverage of a death but the events afterwards and the state funeral* They are known as 'category 1'
https://www.washingtonpost.com/news/worldviews/wp/2015/06/03/the-bbc-goes-to-extraordinary-lengths-to-prepare-for-the-death-of-a-royal/
*that said should anyone who is eligible for a state funeral pass away during this pandemic I imagine that it would be very different from the procedures and protocol that's been around for decades