What?
Virtual public entities put out for tender so-called Public Service Obligations. The winning airline is then obliged to provide a certain level of service on a given route, typically a thin and/or low-yield one that make no commercial sense on its own. The airline then received compensation for this capacity, but might also have to pay penalties if it fails to provide it.
Why?
The original idea for this was actually “a tutorial in disguise”: New players would receive a private offer for a PSO specifically catered to them, providing them with easy, stable income for their start into the game. But this could obviously be made into a general feature by which airlines must compete for PSO contracts. This would add a new potential revenue stream/play-style while also giving more meaning to the thousands of remote and/or small airports in AS.
When?
Implementation could start at any time, no technical dependencies.