TYPO3 Core

Confirmed:
All content elements set to Language = [All] are not shown in the default page module.

Is there any TSconfig switch I might have missed that should be used to show these items in classic Web->Page?

Here is the Page TSconfig trigger, the [All] elements will be shown in the default language column:

mod.web_layout.defLangBinding = 1

From the documentation:
doc_l10nguide:
When using language binding combined with “config.sys_language_overlay = hideNonTranslated” there is a special significance of the language value “[All]” (technically the -1 value): These elements will not be hidden in the translation - and they are not meant to be translated although you can choose to do so.

doc_core_tsconfig:
If set, translations of content elements are bound to the default record in the display. This means that within each column with content elements any translation found for exactly the shown default content element will be shown in the language column next to.
This display mode should be used depending on how the frontend is configured to display localization. The frontend must display localized pages by selecting the default content elements and for each one overlay with a possible translation if found.

So it doesn't make much sense to use the [All] setting and not enable language binding. Maybe the page module could still be improved in this regard, but this would be another issue with some good proposal on what should be done.

Resolved with no change required for now.

This issue might be set as related to a new one if someone comes up with an idea on how to improve the page module it this regard, with the different TS / Page TSconfig switches in mind.