it’s weird. The WARN law requires notice, but, the penalty for violating the law is you have to pay people 60 days of pay. So paying instead of providing notice is technically illegal, but enforcement is pointless if you pay people with no additional conditions. That being said, if you make the pay conditional such as requiring a non disparagement clause, that can be a problem, and is likely going to be a problem here. (Can’t be sure yet, I don’t believe anyone has the details from Twitter yet)
https://webapps.dol.gov/elaws/eta/warn/faqs.asp