There has been an update to NetPlay in general that supports something called "Net Rooms" which would be similar to random match making. However it doesn't work on Retropie at the moment.

https://retropie.org.uk/forum/topic/7913/retroarch-1-4-1-netplay/17

I personally would love to see Retropie to link up with Fightcade https://www.fightcade.com/