Some people seem to have their own interpretations of what SoD supposed to be about, but afaik, what the devs said is that it’s about rediscovering the classic world of Azeroth.
I think dueling, and more specifically 3v3 arenas are a lot of fun, but it’s also instanced lobby-game style play. We have Raids, Instance Dungeons, and Battlegrounds already. SoD has introduced STV Bloodmoon, a new World PVP event, which in my opinion at least, is pretty inline with a Classic world feel (though some have complained that it overshadows the entire zone that was once an iconic WPVP zone to begin with).
Anyway, I’m not personally against your idea… I’d kind of like to see some sort of Arena dressing room type thing, and I’d also like to be able to play my Classic SoD character in Wrath or Retail Arenas somehow.