Narrator credit in IMDb even when not credited on-screen?

Question about a Narrator credit for episodes of a TV series, even when there isn't an on-screen credit during the original broadcast.

Situation: During the original broadcast, sometimes the show has credits (which show the narrator), and sometimes it doesn't. However, the same episodes shown online after the original broadcast, do have on-screen credits.

So my question is, why can't this person have a "(voice) (uncredited)" attribute?  The narrator has obviously done the work, and has received on-screen credit, but just not during the original broadcast.

Yes, I know this is not consistent with the policy stated here:
https://help.imdb.com/article/contribution/filmography-credits/cast-acting-credits-guidelines/GH3JZC...

So I guess is what I'm asking is for an exception.  Submission 181204-164309-946000