As the first paragraph of that article points out, advance notice is required by federal law, if the company is sufficiently large and if sufficiently many people are being laid off at the same time. At-will employment is not relevant.
Yeah, the Warn Act doesn’t require you let them work for 60 days. If it’s triggered, it just means you have to pay them for 60 days. It is very common to not let them work, particularly when concerned about sabotage.
Sure. I haven't seen the actual legal complaint, so I don't know if it's just a publicity stunt, or if they actually have evidence that Musk is planning to not pay out the extra wages that he's (presumably) required to.
That probably works in the US but in some jurisdictions (e.g. parts of Europe) -- where I presume Twitter has [or had!] employees -- there are requirements for an actual consultation process before substantial layoffs.
You can give them notice when the decision is yours to make. And the then the termination can be legal at X days beyond that, if the legal requirement is X days notice. I don't see how "I Just bought it" matters?
https://en.wikipedia.org/wiki/Worker_Adjustment_and_Retraini...