Here is the caselaw for the last time Tesla got sued under WARN Act:
https://casetext.com/case/lynch-v-tesla-inc
https://www.docketalarm.com/cases/Texas_Western_District_Cou...
It gives a good summary of what the law is about
It eventually got settled via arbitration:
https://lawstreetmedia.com/news/tech/tesla-workers-warn-act-...