The company has never publicized the rules and regulations, but it is legal for employees to sign the note "I know and agree with all the rules and regulations of the company".

This is a serious violation of the law, forcing employees to sign the overlord clause, and what's more, it is prostitution that ignores the life and death of employees. In this case, the employee should flatly refuse, because once you sign it, it is equivalent to signing a life and death contract, and everything you have is not guaranteed. You can report this situation to the local labor department to avoid others being hurt.