bug#45234: Annotation function vs. Affixation function

[clemera]

On current master the results of the new annotation function are passed 
to the affixation function in minibuffer-completion-help:

    (when ann-fun
      (setq completions
            (mapcar (lambda (s)
                      (let ((ann (funcall ann-fun s)))
                        (if ann (list s ann) s)))
                    completions)))     (when aff-fun
      (setq completions
            (funcall aff-fun completions)))

If the annotation function returns a result it's packed into a list
which should be an unexpected format for the affixation function?
Maybe when both are defined only the affixation function should be used?