The OP was asking what happens to productivity when your LLM is offline, I'd assume it isn't available yo onboard anyone at that time either.

More importantly I think, if devs become dependent enough on LLMs that they just put it aside when the model isn't available, they wouldn't be able to onboard quickly or at all.

It takes experience and a pretty deep understanding of programming in your language of choice to pick up a new code base and quickly understand how it works, the architecture(s) and pattern(s) being used, etc. Those skills would likely have been lost long before a dev simply can't work without the LLM.