Are you currently using the plugin generator from
node scripts/generate_plugin.js when checking out the master branch of the Kibana repo?
There are few places left in Kibana still relying on AngularJS - and even those are scheduled to be removed soon.
You can still build your plugin using AngularJS, but it's not recommended and you won't be able to leverage the "Kibana angular" in a meaningful way. If you still want to do it, you should bootstrap angular on your own into the dom element passed to you in the "mount" function in the plugin class (
params.element) - from there it's just like a regular angular app not really tied to Kibana.