Not just about California law, but he explains when a Layoff might be unlawful, and how a lawyer might have to prove it.
Is the company still making money or is it losing money. Is this retaliation for bringing up a safety issue somehow. Are you in a protected class, of race, gender, sexual orientation, disability?
Mentions that the 60 day warning period of the WARN act only applies to certain employers and is not very powerful.
Does not mention Work From Home situations, and I am guessing that is not a protected class, unless it involves a disability (ADA). Can an employer justify sending people to work (in an office at some distance) if they cannot prove a need? Can they prove the employee is more productive at an office after the commute and distractions? I do not know.
There might be an implied contract between you and the employer if you were hired to work from home, I am guessing, and the employer is suddenly changing the terms of the contract without your permission. A contract is a legal obligation between two parties and you would have to prove there was a contract. It might not be in writing, so this might complicate things.
Anyway the attorney in the video also has related videos fwiw, how can you quit your job, FMLA, “Toxic Work Environment”, how HR can cheat you, etc. Video: https://www.youtube.com/watch?v=oCxo50g-6ZQ