This is what their blog post says: `GPT-5 will be rolling out to all paid Copilot plans, starting today. You will be able to access the model in GitHub Copilot Chat on github.com, Visual Studio Code (Agent, Ask, and Edit modes), and GitHub Mobile through the chat model picker. Continue to check back if you’ve not gotten access.`
I think "starting today" might be doing some heavy lifting in that sentence.
https://github.blog/changelog/2025-08-07-openai-gpt-5-is-now...