I don't think it will be a possible location of El Dorado because Avernus is just like Dragonspyre, El Dorado is also a city of solid gold, the stormgate doesn't appear twice in the same place, and in the puppet show, told by Cpt. Avery, it said it was impossible to get there, so I believe that there won't even be a stormgate. Might be something secret like a place to go beyond a skyway in the spiral. Don't ya think?
There are various unused stormgates in different worlds, presumably intended to be named as the world to which they lead becomes open to us (or KI gets around to making those worlds). I don't think I'd hold my breath for this one to be The Stormgate, if you will.
Well, Avernus is a really dark skyway so that stormgate I must assume must lead to something as "dark" as an area maybe Darkmoor but who knows, maybe what is coming on October 15th could be a new world OR Valencia Part 2.
Sorry, I may not no much, I only just started Mooshu