Blizzard has stated somewhere...either news or a possible blue post I don't remember precisely but the RTS Warcraft is not out of question right now, and it's still possible and even useful to them still or to possibly further warcraft story. If you want to actually find the exact info I'm sure a true forum hero can find it so ya.
Also to the one guy about the Burning Legion not having a homeworld isn't completely true either considering people take into account how it was made and by which titans and why, which wowhead and other sites explain.
To the OP, I want it to be the next Burning Legion xpac on some new world, so sick of azeroth honestly, but the other people saying it will be old gods first then burning legion I'm thinking are correct. Only time will tell.