Better to get Layed off on EAD than on H1B

[gsk]

I heard in ISN discussion board that its safe to get layed off on EAD rather than
    on H1B.

    I have both H1B and EAD, and I am using H1B currently.. I know we have to fillup
    I-9 form with the company to get switched to EAD.

    Question: How do INS know that we switched from H1B to INS since this form
    is filledup only with the comapny and it is not going to be forwarded to INS ?

    Can we fillup up this I-9 form anytime before get layed off ?

    Thanks
    Venu.