I think it just means "let go not because of individual performance" as opposed to "fired" meaning "let go because of bad individual performance."

It think of it in the sense that you are talking about though because I grew up with a lot of people in the building trades. They often use "laid off" to mean basically "there's not enough work so I'm not getting hours until there is more" (eg temporary). But I think that is pretty specific to those industries where there is pretty fixed pool of labor and the work is highly seasonal.

Interesting, apparently it used to mean either, without prescribing a timeframe:

https://en.wikipedia.org/wiki/Layoff

I think the meaning has fully shifted to imply permanence, for at least a couple decades now. The word that comes to mind for a temporary situation is furlough, although I’ve mainly heard that used in a government context.

Maybe the difference is that most people now change jobs often enough, that the government is the only entity that would promise to re-employ those they temporarily couldn’t pay.

I don't think so. If it's meant to be temporary, doesn't it get called a furlough instead? That's the "we're not firing you because we want you to do work for us later, but also we're going to stop paying you" option.

The most common reason I heard in their announcements was that they drastically over-hired during the pandemic and needed to downsize to adjust to "market conditions". Are they saying market conditions have substantially improved?