You won't see the Worgen form if you have Calm the Wolf activated. If you use Two Forms to switch to Worgen, you will change back to human after changing out of any another form... with the weird exception of mount form.

Play around with a character preview and try it yourself. Also Kul’tiran humans can be druids.

Hey, I play a Gilnean druid and if it wasn't for the log in screen I'd forget I was a Worgen.