Specs clarification: `type[A | B]` is equivalent/the same as `type[A] | type[B]`

Thanks for raising this issue @InSync. It’s one of the points I raised in Clarifications to the typing spec regarding `type[]`. I have a draft PR locally addressing it and some other issues discussed in that earlier thread, but haven’t yet got round to polishing the PR and submitting it — so thanks for pushing this forward.