Hugging Face being developer-facing is completely irrelevant considering the question you asked was whether I was aware of any companies doing anything like this.

Your concern that companies like Meta and Microsoft are too scared to let users retrain their models is also irrelevant considering both of these companies have already released models so that anyone can retrain or checkpoint merge them i.e. Llama by Meta and Phi by Microsoft.

It’s a cloned image, not unique per computer

Microsoft's Copilot works off a base model, yes, but just an example that LLMs aren't as CPU intensive as made out to be. Further automated finetuning isn't out of the realm of possibility either and I fully expect Microsoft to do this in the future.