It has nothing to do with machine learning. It has everything to do with current capabilities of drones. If we develop drones the size of combat aircraft then maybe some day people can fly them remotely as we do current drones. Eventually they may be as efficient as manned aircraft, but the technology isn't there yet which means fighter aircraft isn't over yet. The design of what they do has changed however. Dogfighting isn't a big priority any longer. That seems to be far less important than bombing runs, protecting assets on the ground, etc... Those can't be done by drones yet.
I'm also not certain I'm even close to being ready to trusting an AI to choose who gets to live or die though.