Its pretty simple, they wont, 3rd party devs make what they want and are capable to make if they can't they will make nothing.
There is no need for entire theatres to come with every aircraft, when there is a critical mass of aircraft of an era then someone will step up and make one just like RRG with ww2.
They seem to be going in the right direction to me, building the foundation for many others to make sims.