140 Approval after being laid off

My case (RD 10/08/2005, PD 03/2003, concurrent filing) was approved today. It was transferred from CSC to TSC on March 22nd.

It is a miracle for me, or I am not sure. I was laid off end of April and luckily for me, I found another similar job with H-1B transfer.

So I have two questions:

1. Is this I-140 valid? (I guess my previous company did not, or have not withdrwal it), can it be ported to my current employer via AC21?

2. What will happend if my previous employer try to revoke it later? It has been pending, along with my I-485, over 180 days (even when I was laid off) at USCIS. So theoratically, it can not be revoked even I no longer work for my previous employer?

Thank you for your help and suggestion