Yeah, I got the email that they removed them from the student plan:
"As part of this transition, however, some premium models, including GPT-5.4, and Claude Opus and Sonnet models, will no longer be available for self-selection under the GitHub Copilot Student Plan."
They specifically said this was primarily for student plans. I'm surprised they did this for the normal pro plans too; it's likely a mistake since the plans page[1] still says that the models will be available.
However, TBH, I've never liked Microsoft's flavor of these; they always seem lobotomized compared to using the models directly in Claude Code / Codex. I rarely use AI in VS Code because it's just bad.
[1]: https://docs.github.com/en/copilot/get-started/plans