Ok, great, so Microsoft believes in open weight models. So... uhh, why not release a few?

They did. Check out the Phi models (e.g., https://huggingface.co/microsoft/phi-4).

Great, how about some frontier models like China seems to be doing on a weekly basis at this point. Give us a CoPilot variant that's open source & open weights.

They could start by releasing the MAI-1 models they announced recently. https://microsoft.ai/models/