Which models are affected?
GitHub’s 15 October notice sets 16 November 2026 as the retirement date for Claude Opus 4.8, Claude Opus 5 and GPT-5.6 Terra across Copilot experiences.
Opus 4.8 remains available to individual Copilot subscribers on annual plans. That exception does not extend to the other two models.
Alternatives and organization controls
GitHub suggests Opus 5.5 for the two Opus models, and GPT-6.1 Sol or GPT-6 Luna for Terra. These are GitHub’s suggestions; Fewertools has not evaluated a new comparative winner.
Business and Enterprise alternatives follow default model enablement unless an administrator disables the global default or the particular model. Access can require a policy change. Account eligibility and workflow compatibility were not tested here.
Related workflow context
The separate Slack and Teams update adds multi-repository conversations. Keep that client change separate from the model retirement deadline.
See the dated Copilot profile, Cursor/Copilot comparison and coding task worksheet.
Source scope
Official notices read on 16 October. No coding task, performance comparison or current price was tested. Claim receipts.