Prep docs for deprecation of Gemini 3 Pro and GPT-5.1 model family (#60323)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: sunbrye <56200261+sunbrye@users.noreply.github.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Co-authored-by: sunbrye <sunbrye@github.com>

Author: 3 people

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

@@ -92,7 +92,7 @@ These models are designed for tasks that require step-by-step reasoning, complex
 | {% data variables.copilot.copilot_gpt_54 %}           | Great at complex reasoning, code analysis, and technical decision-making.                                                                                       |
 | {% data variables.copilot.copilot_claude_sonnet_46 %} | Improves on Sonnet 4.5 with more reliable completions and smarter reasoning under pressure.                                                                     |
 | {% data variables.copilot.copilot_claude_opus_46 %}   | Anthropic’s most powerful model. Improves on {% data variables.copilot.copilot_claude_opus_45 %}.                                                               |
-| {% data variables.copilot.copilot_gemini_3_pro %}     | Advanced reasoning across long contexts and scientific or technical analysis.                                                                                   |
+| {% data variables.copilot.copilot_gemini_31_pro %}    | Advanced reasoning across long contexts and scientific or technical analysis.                                                                                   |
 | {% data variables.copilot.copilot_goldeneye %}        | Complex problem-solving challenges and sophisticated reasoning.                                                                                                 |
 
 ### When to use these models
@@ -118,7 +118,7 @@ Use these models when you want to ask questions about screenshots, diagrams, UI
 |-------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | {% data variables.copilot.copilot_gpt_5_mini %}       | Reliable default for most coding and writing tasks. Fast, accurate, and supports multimodal input for visual reasoning tasks. Works well across languages and frameworks. |
 | {% data variables.copilot.copilot_claude_sonnet_46 %} | Improves on Sonnet 4.5 with more reliable completions and smarter reasoning under pressure.                                                                               |
-| {% data variables.copilot.copilot_gemini_3_pro %}     | Deep reasoning and debugging, ideal for complex code generation, debugging, and research workflows.                                                                       |
+| {% data variables.copilot.copilot_gemini_31_pro %}    | Deep reasoning and debugging, ideal for complex code generation, debugging, and research workflows.                                                                       |
 
 ### When to use these models
 

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

@@ -76,11 +76,10 @@ When using {% data variables.copilot.copilot_claude %}, input prompts and output
 Used for:
 
 * {% data variables.copilot.copilot_gemini_25_pro %}
-* {% data variables.copilot.copilot_gemini_3_pro %}
 * {% data variables.copilot.copilot_gemini_3_flash %}
 * {% data variables.copilot.copilot_gemini_31_pro %}
 
-{% data variables.product.prodname_copilot %} uses {% data variables.copilot.copilot_gemini_31_pro %}, {% data variables.copilot.copilot_gemini_3_pro %}, {% data variables.copilot.copilot_gemini_3_flash %}, and {% data variables.copilot.copilot_gemini_25_pro %} hosted on Google Cloud Platform (GCP). When using {% data variables.copilot.copilot_gemini %} models, prompts and metadata are sent to GCP, which makes the [following data commitment](https://cloud.google.com/vertex-ai/generative-ai/docs/data-governance): _{% data variables.copilot.copilot_gemini %} doesn't use your prompts, or its responses, as data to train its models._
+{% data variables.product.prodname_copilot %} uses {% data variables.copilot.copilot_gemini_31_pro %}, {% data variables.copilot.copilot_gemini_3_flash %}, and {% data variables.copilot.copilot_gemini_25_pro %} hosted on Google Cloud Platform (GCP). When using {% data variables.copilot.copilot_gemini %} models, prompts and metadata are sent to GCP, which makes the [following data commitment](https://cloud.google.com/vertex-ai/generative-ai/docs/data-governance): _{% data variables.copilot.copilot_gemini %} doesn't use your prompts, or its responses, as data to train its models._
 
 To provide better service quality and reduce latency, {% data variables.product.github %} uses [prompt caching](https://cloud.google.com/vertex-ai/generative-ai/docs/data-governance#customer_data_retention_and_achieving_zero_data_retention).
 

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

@@ -11,6 +11,26 @@
 # - retirement_date: The official retirement date for the model (YYYY-MM-DD).
 # - suggested_alternative: The model recommended for migration.
 
+- name: 'GPT-5.1'
+  retirement_date: '2026-04-01'
+  suggested_alternative: 'GPT-5.3-Codex'
+
+- name: 'GPT-5.1-Codex'
+  retirement_date: '2026-04-01'
+  suggested_alternative: 'GPT-5.3-Codex'
+
+- name: 'GPT-5.1-Codex-Max'
+  retirement_date: '2026-04-01'
+  suggested_alternative: 'GPT-5.3-Codex'
+
+- name: 'GPT-5.1-Codex-Mini'
+  retirement_date: '2026-04-01'
+  suggested_alternative: 'GPT-5.3-Codex'
+
+- name: 'Gemini 3 Pro'
+  retirement_date: '2026-03-26'
+  suggested_alternative: 'Gemini 3.1 Pro'
+
 - name: 'Claude Opus 4.1'
   retirement_date: '2026-02-17'
   suggested_alternative: 'Claude Opus 4.6'

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

@@ -34,28 +34,28 @@
 
 - name: 'GPT-5.1'
   provider: 'OpenAI'
-  release_status: 'GA'
+  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: 'GA'
+  release_status: 'Closing down: 2026-04-01'
   agent_mode: true
   ask_mode: true
   edit_mode: true
 
-- name: 'GPT-5.1-Codex-Mini'
+- name: 'GPT-5.1-Codex-Max'
   provider: 'OpenAI'
-  release_status: 'Public preview'
+  release_status: 'Closing down: 2026-04-01'
   agent_mode: true
   ask_mode: true
   edit_mode: true
 
-- name: 'GPT-5.1-Codex-Max'
+- name: 'GPT-5.1-Codex-Mini'
   provider: 'OpenAI'
-  release_status: 'GA'
+  release_status: 'Closing down: 2026-04-01'
   agent_mode: true
   ask_mode: true
   edit_mode: true
@@ -161,13 +161,6 @@
   ask_mode: true
   edit_mode: true
 
-- name: 'Gemini 3 Pro'
-  provider: 'Google'
-  release_status: 'Public preview'
-  agent_mode: true
-  ask_mode: true
-  edit_mode: true
-
 - name: 'Gemini 3.1 Pro'
   provider: 'Google'
   release_status: 'Public preview'