I noticed this as well. Sorry if I’m just being dense, but I’m not sure how the priority could matter here, as the same variable is passed in both parameters.
/**
* Filters the $value before it is updated.
*
* @date 28/09/13
* @since 5.0.0
*
* @param mixed $value The value to update.
* @param string $post_id The post ID for this value.
* @param array $field The field array.
* @param mixed $original The original value before modification.
*/
$value = apply_filters( "acf/update_value", $value, $post_id, $field, $value );
I would also expect a call to grab the original value before line 188 if the original value was intended to be passed.
