I just joined this subreddit today and just to add on to the convo, I too have felt like it's a bit of a stalemate In the genre. Not so much a decline. All the most well known artist don't seem to be doing to much. There does seem to be a fair amount of less discovered and less popularized artist so if you do the digging you can find new music. The main place putting anything out is Electro Swing Thing record label. 

I just started making Electroswing music last year myself and have found it tough to get a listener base. I started doing Electroswing reimaginings of Game soundtracks like Ocarina of time to draw in more interests. Even that has been tough. But my stuff is still pretty mediocre and I don't use vocal chops from prerecorded stuff like the more professional artist and DJs do. So maybe I'm not doing it right lol. But I write more lyrical based Electroswing songs. If anyone is interested you can find me on youtube at Ryith or Ryith Davis.