The reason is that ASW, the company that makes it, is kinda ADD and is currently maintaining three major fighting game series: Persona, Guilty Gear, and BlazBlue. The games are similar enough that they mostly share a common fanbase, and those fans only have time for one game at a time. So generally, Evo will run…

They didn't just expand to Namco and SNK, those series have been staples for years. They're also not even playing Mortal Kombat. And literally nobody outside of Japan plays VF. It would get like 20 entrants.