Document permanently unavailable features on GHE.com (#58676)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: isaacmbrown

content/admin/data-residency/feature-overview-for-github-enterprise-cloud-with-data-residency.md

@@ -16,19 +16,27 @@ redirect_from:
 
 ## Currently unavailable features
 
-The following features are currently unavailable on {% data variables.enterprise.data_residency_site %}.
+The following features are currently unavailable on {% data variables.enterprise.data_residency_site %}, but may be planned for future development.
 
 | Feature | Details | More information |
 | :- | :- | :- |
-| {% data variables.product.prodname_copilot_short %} Metrics API | Currently unavailable | [AUTOTITLE](/rest/copilot/copilot-metrics) |
+| {% data variables.product.prodname_copilot_short %} Metrics API | Currently unavailable. | [AUTOTITLE](/rest/copilot/copilot-metrics) |
 | {% data variables.product.prodname_github_codespaces %} | Currently unavailable. | [AUTOTITLE](/codespaces/quickstart) |
-| {% data variables.product.prodname_importer %} (the "Import repository" button on {% data variables.product.prodname_dotcom_the_website %}) | Instead, the **{% data variables.product.prodname_importer_proper_name %}** is available to migrate data. See [AUTOTITLE](/migrations/using-github-enterprise-importer/understanding-github-enterprise-importer/about-github-enterprise-importer). | [AUTOTITLE](/migrations/importing-source-code/using-github-importer/about-github-importer) |
-| {% data variables.product.prodname_marketplace %} | Currently, apps from {% data variables.product.prodname_marketplace %} are unavailable. {% data variables.product.prodname_actions %} workflows from {% data variables.product.prodname_marketplace %} may not function as expected. For more information, see [{% data variables.product.prodname_actions %} workflows from {% data variables.product.prodname_marketplace %}](#github-actions-workflows-from-github-marketplace). | [AUTOTITLE](/search-github/searching-on-github/searching-github-marketplace)<br>[AUTOTITLE](/enterprise-server@latest/admin/configuration/configuring-github-connect/about-github-connect#github-connect-features) in the {% data variables.product.prodname_ghe_server %} documentation |
-| {% data variables.product.prodname_github_models %} |  Currently unavailable | [AUTOTITLE](/github-models/about-github-models) |
 | macOS runners for {% data variables.product.prodname_actions %} | Currently unavailable. | [AUTOTITLE](/actions/using-github-hosted-runners/about-github-hosted-runners/about-github-hosted-runners) |
 | Maven and Gradle support for {% data variables.product.prodname_registry %} | Currently unavailable. | [AUTOTITLE](/packages/working-with-a-github-packages-registry/working-with-the-apache-maven-registry) |
-| {% data variables.product.prodname_spark_short %} | Unavailable due to dependency on {% data variables.product.prodname_github_codespaces %} | [AUTOTITLE](/copilot/concepts/spark) |
-| Some features currently in {% data variables.release-phases.public_preview %} or {% data variables.release-phases.private_preview %} | Certain features that are in a preview phase on {% data variables.product.prodname_dotcom_the_website %} may not be available on {% data variables.enterprise.data_residency_site %} | |
+| {% data variables.product.prodname_spark_short %} | Currently unavailable. | [AUTOTITLE](/copilot/concepts/spark) |
+| {% data variables.product.prodname_marketplace %} | {% data variables.product.prodname_marketplace %}, as a means of searching for, purchasing, and directly installing apps and actions, is unavailable. Ecosystem apps and actions can still be discovered and installed from their source, but they may require modification to work on {% data variables.enterprise.data_residency_site %}. | [{% data variables.product.prodname_actions %} workflows from {% data variables.product.prodname_marketplace %}](#github-actions-workflows-from-github-marketplace) |
+| Certain features of {% data variables.product.prodname_github_connect %} | Although you can connect an enterprise on {% data variables.enterprise.data_residency_site %} to a {% data variables.product.prodname_ghe_server %} instance, certain features of {% data variables.product.prodname_github_connect %} are not available, including resolution of actions from {% data variables.product.prodname_dotcom_the_website %}. | [{% data variables.product.prodname_github_connect %}](#github-connect) |
+| Some features currently in {% data variables.release-phases.public_preview %} or {% data variables.release-phases.private_preview %} | Certain features that are in a preview phase on {% data variables.product.prodname_dotcom_the_website %} may not be available on {% data variables.enterprise.data_residency_site %} until GA. | |
+
+## Permanently unavailable features
+
+By design, the following features are permanently unavailable on {% data variables.enterprise.data_residency_site %}. This is generally because they are not intended for large enterprises with strict compliance requirements.
+
+| Feature | Details | More information |
+| :- | :- | :- |
+| Features unavailable with {% data variables.product.prodname_emus %} | Because {% data variables.product.prodname_emus %} is the only option for identity management on {% data variables.enterprise.data_residency_site %}, features that are unavailable with {% data variables.product.prodname_emus %} on {% data variables.product.prodname_dotcom_the_website %} are also unavailable on {% data variables.enterprise.data_residency_site %}. Notably, these include gists and public repositories. | [AUTOTITLE](/admin/managing-iam/understanding-iam-for-enterprises/abilities-and-restrictions-of-managed-user-accounts) |
+| {% data variables.product.prodname_importer %} (the "Import repository" button on {% data variables.product.prodname_dotcom_the_website %}) | Instead, the **{% data variables.product.prodname_importer_proper_name %}** is available to migrate data. See [AUTOTITLE](/migrations/using-github-enterprise-importer/understanding-github-enterprise-importer/about-github-enterprise-importer). | [AUTOTITLE](/migrations/importing-source-code/using-github-importer/about-github-importer) |
 
 ## Features that work differently