AngularJS - ng-disabled not working for Anchor tag

There is no disabled attribute for hyperlinks. You can do this:

.disabled {
  cursor: not-allowed;
}

<a ng-click="disabled()" ng-class="{disabled: addInviteesDisabled()}">Add</a>

$scope.disabled = function() {
  if($scope.addInviteesDisabled) { return false;}
}

You could create a linkDisabled css class, and apply it to your anchor:

<style>

.linkDisabled {
  cursor: not-allowed;
  pointer-events: none;
  color: grey;
}

</style>