deprecate 5.1 family (#60598)

Author: sunbrye

content/copilot/reference/ai-models/model-hosting.md

@@ -21,9 +21,6 @@ Used for:
 * {% data variables.copilot.copilot_gpt_41 %}
 * {% data variables.copilot.copilot_gpt_5_mini %}
 * {% data variables.copilot.copilot_gpt_51 %}
-* {% data variables.copilot.copilot_gpt_51_codex %}
-* {% data variables.copilot.copilot_gpt_51_codex_mini %}
-* {% data variables.copilot.copilot_gpt_51_codex_max %}
 * {% data variables.copilot.copilot_gpt_52 %}
 * {% data variables.copilot.copilot_gpt_52_codex %}
 * {% data variables.copilot.copilot_gpt_53_codex %}

content/copilot/reference/ai-models/supported-models.md

@@ -66,11 +66,6 @@ The following table shows which models are available in each client.
 > [!NOTE]
 > * {% data reusables.copilot.auto-model-selection %}
 > * {% data reusables.copilot.gpt-5-codex-vscode-support %}
-> * {% data variables.copilot.copilot_gpt_51_codex %} and {% data variables.copilot.copilot_gpt_51_codex_mini %} are supported in: 
->   * Visual Studio Code versions 1.104.1 or higher
->   * JetBrains, Copilot plugin versions 1.5.61 or higher
->   * Xcode, Copilot plugin versions 0.45.0 or later
->   * Eclipse, Copilot plugin versions 0.13.0 or later 
 
 {% rowheaders %}
 

data/reusables/copilot/copilot-coding-agent-non-auto-models.md

@@ -1,4 +1,3 @@
 * {% data variables.copilot.copilot_claude_opus_45 %}
 * {% data variables.copilot.copilot_claude_opus_46 %}
-* {% data variables.copilot.copilot_gpt_51_codex_max %}
 * {% data variables.copilot.copilot_gpt_52_codex %}

data/tables/copilot/model-deprecation-history.yml

@@ -12,7 +12,7 @@
 # - suggested_alternative: The model recommended for migration.
 
 - name: 'GPT-5.1'
-  retirement_date: '2026-04-01'
+  retirement_date: '2026-04-15'
   suggested_alternative: 'GPT-5.3-Codex'
 
 - name: 'GPT-5.1-Codex'

data/tables/copilot/model-release-status.yml

@@ -34,28 +34,7 @@
 
 - name: 'GPT-5.1'
   provider: 'OpenAI'
-  release_status: 'Closing down: 2026-04-01'
-  agent_mode: true
-  ask_mode: true
-  edit_mode: true
-
-- name: 'GPT-5.1-Codex'
-  provider: 'OpenAI'
-  release_status: 'Closing down: 2026-04-01'
-  agent_mode: true
-  ask_mode: true
-  edit_mode: true
-
-- name: 'GPT-5.1-Codex-Max'
-  provider: 'OpenAI'
-  release_status: 'Closing down: 2026-04-01'
-  agent_mode: true
-  ask_mode: true
-  edit_mode: true
-
-- name: 'GPT-5.1-Codex-Mini'
-  provider: 'OpenAI'
-  release_status: 'Closing down: 2026-04-01'
+  release_status: 'Closing down: 2026-04-15'
   agent_mode: true
   ask_mode: true
   edit_mode: true