> does this mean that after leaving a job on an H1B visa, a worker has 60 days to potentially find another job?

Yes. The content of the actual rule can be found at: https://www.gpo.gov/fdsys/pkg/FR-2016-11-18/pdf/2016-27540.p.... It says:

    Nonimmigrants in certain high-skilled, nonimmigrant classifications may 
    be granted grace periods of up to 10 days before and after their validity 
    period, and a grace period upon cessation of employment on which the 
    foreign national’s classification was based, for up to 60 days or until the 
    end of their authorized validity period, whichever is shorter, during each 
    authorized validity period.

PS: IANAL etc.