employer will withdraw I-140, 怎麽辦. (I-485 pending over 180 days)

Today i am laid off. Termination day is today.
HR noted that the company will notify USICS after 30 days of the H1B termination and will withdraw the non-immigration visa petition(I-140?).

what is the reason for the company to do this? I know not every company is doing this. I want to know the situation and see if I can talk to HR not doing this if possible.

Any ideas will be appreciated!