I don't read this as employing 20% was twiddling their thumbs and sitting around.
If it means anything beyond economic issues, I read the implication as their LLM expenses have gone threw the roof and with the choice of cutting LLM use or cutting headcount, well we see what mattered more to them.
Those 20% were unproductive in the literal sense or the economic sense.
Unfortunately I think we’ll see more and more of this as companies continue to encourage their employees to use LLMs everywhere and for everything. Eventually they will have to come to terms with the cost of such mandates, and it’s either ask your employees to “use AI less,” or it’s let some percentage go and continue to let the rest burn tokens.