What happens when Microsoft stops using ChatGpt as their main LLM for CoPilot? I feel the death knell when that occurs

just today, MS announced that gpt-5.3-codex will become Copilot’s new base model. It is also the first LTS model that will be supported until 2027.

https://github.blog/changelog/2026-03-18-gpt-5-3-codex-long-...

That's github copilot though, which is different (gh is msft, but here you have the option to choose other models too). Their regular copilot app and the one on windows still uses oai as their base model, which can hurt oai, if they choose to move away from it

i'm confused - did you miss that codex 5.3 is also an openai model?

It's unlikely to happen because of the deal MS has with OAI. It's hard to ignore a percentage of revenue as money back guarantee