I think the BBC’s reporting angle is a consequence of the two parties that have governed over the last century seeing a dramatic decline in their support and a different party topping the poll, albeit at a level not equal to what the other parties used to get.
No matter what anyone might think about that personally, it is newsworthy. And while it is too early and perhaps unwise to project these results onto a General Election, I suspect they will not be too far off what eventually happens, especially if Starmer stays on.