Druids are shapeshifters. Yes, that is true, to an extent. You have multiple forms, and you can move (almost) freely between them. I'm gonna go back to WC3 for an argument. Malfurion never shifted. Ever. His druids of both claw and talon stayed in caster form much of the time, because it was strategic to do some of what we call caster form and some of their shifted forms. Staying always in form was considered BAD, lorewise. The druids of the claw went insane because they stayed in bear form so much, and it took the influence of Cenarius to fix that.

Then there's another thing. Shapeshifting may be your core class mechanic, but it is not your core class issue. If you want something connected to the mainstay of druidism, why don't druids have an Emerald Dream-related ability? Maybe that's something you'll get, if not in this expansion, then in one more directly connected to the Emerald Dream and the Nightmare. I'd certainly like to see it, as it would be a return to the original concept of what a druid is.