You do understand that it takes years to plan, design and build new satellites, by that time DirecTV and Dish ( they have no new satellites planned either) will have lost so many customers and the economics of satellite TV will be so bad, it will be obvious the business is in a death spiral.
Also do not forget about new equipment, boxes, they also have nothing planned and they can take years to develop, especially now since they have no one doing so.
Lastly, even if they do sell all of DirecTV, that will take at least a year ( Government), it is not like change the locks and lets launch a new bird, it will be 2-3 years after a sell to do that, 4 years from now.
I know you have doubts about Star Link, but you better hope it works out, it might be the only hope for rural folks.