It's not a bug. You are specifying the choices when the form is
defined, and at that point there is nothing in the database and so the
form has no choices. Since the field is never redefined in the form,
the choices will be whatever existed in the database when the form is
defined, which is a bad way of designing the form.
Typically, when your choices are instances of a model, you would not
use ChoiceField, but ModelChoicefield. ModelChoiceField takes a
queryset when defining the form, and avoids evaluating the queryset
until the form is instantiated, which avoids the issue. The
documentation also explains how you can specify the queryset more
dynamically if that is required.
https://docs.djangoproject.com/en/1.8/ref/forms/fields/#modelchoicefield
(I'm assuming that the typo "choises" is only present in your email,
and your code correctly says "choices" and "ChoiceField")
Cheers
Tom