symfony: Regression in Form extension since 3.2

Since Symfony 3.2 RC 1, I see a regression in my web app: I have a form extension that disable csrf-protection on the /yolo/* routes:

use Symfony\Component\Form\AbstractTypeExtension;
use Symfony\Component\Form\Extension\Core\Type\FormType;
use Symfony\Component\HttpFoundation\RequestStack;
use Symfony\Component\OptionsResolver\OptionsResolver;

class YoloCsrfDisablerExtension extends AbstractTypeExtension
{
    private $requestStack;

    public function __construct(RequestStack $requestStack)
    {
        $this->requestStack = $requestStack;
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $request = $this->requestStack->getCurrentRequest();

        if (null === $request) {
            return;
        }

        if (0 !== strpos($request->getPathInfo(), '/yolo/')) {
            return;
        }

        $resolver->setDefaults([
            'csrf_protection' => false,
        ]);
    }

    public function getExtendedType()
    {
        return FormType::class;
    }
}

Prior to Symfony 3.2, when I submitted a form that failed on validation, errors returned by the form submission returned something like: The value should not be blank.

Since Symfony 3.2, even if the form extension is enabled, I now got two errors: The value should not be blank and The CSRF token is invalid. Please try to resubmit the form. that should not appear since the option is disabled with my extension