I had I140 approval more than 180 days but now previous employer revoked my I140 in Apr 2017. Can I apply H4 EAD now?

FYI. I have changed my status from L1B to H1B last year and last month H4 got approved. I came to know that my previous employer revoked my current I140 approval. I had I140 approval more than 180 days but now they have revoked my I140. One of my colleague told that from Jan 17th 2017 no employer can revoke the I140 If the I140 approval duration is more than 180 days. Could you please clarify in detail. Can I apply H4 EAD now? Please advice.