ac21 - inform INS
I asked my lawyer the same question some days back.
Her response was:
".............INS would typically be advised of a job change in the course of responding to a request for evidence........."
The senate version of the ac-21 law doesn't have any text on this issue.
The INS memo on AC21-law says: ".......Under present practices it is expected that an I-485 applicant notify the Service when they no longer intend to enter into employment with the employer who sponsored them on the I-140 petiton. The Service should continue to expect the applicant to submit a letter notifying INS of this change in intent, if the Adjudicator has reason to believe that the applicant's intent has changed, a Request of Evidence (RFE) may be issued to clarify the applicant's intent in regards to employment.........."
It does not mention anything if the company lays-off the employee. Because, in that case, the employee's intention has not changed, the company's intention has changed.
The above is my personal understanding. Please, consult a lawyer for clear suggestions.