As the article states, the figures prove that unfortunately the buying public don't want saloons or estates anymore.
It's a vicious circle. Sales figures for certain market segments force manufacturers to stop developing those vehicles as the development and production costs, even with platform sharing, can't be covered by the future sales of those vehicles if sales statistics are showing that's the direction the market is going. Less of those cars on the road and in the showroom mean the public are less aware that they exist, so are not on their radar when it comes to thinking about a new car...
It comes down to packaging too. With the move to electrics, its easier to package batteries in a SUV shaped car (under the passenger compartment) then it is to find space for them elsewhere. The Tesla X & Y, most of the Etron Audi's, Merc EQs and Renault/Citroen 'SUVs' etc no longer have the ground clearance you'd associate with SUV's as that's been negated by placing the batteries there. More and more electric cars will follow suit and that traditional SUV selling point will largely disapear.