Too much? They're worse with Overwatch than they were some years back without Overwatch. And Overwatch was Blizzard's "star" for the last years. That actually means something. And that WoW is on the low end when it comes to subs should be quite obvious, too. Low MAUs musn't be bad when Blizzard reacts to the situation appropriately (e.g. stepping up their game like they did after WoD).
Regarding Dragon Isles... what would be the zones? The continent? Where is it? *POOOOF* and it's just right next to Broken Isles and Kul Tiras? Where has it been the last years? Another island like content yeah that's something we really need. You know something that could work imho? A continent that's NOT on the surface of Azeroth, meaning it's 1) flying / floating, 2) underwater or 3) cave like. I don't want another universe/planet so when it comes to Dragon Isles I'd like it to be a floating continent.