A very nice female IO answered my call:
Me:I was wondering what's the most update status of my I-485 application?
IO: What's your case # and would you verify your date of birth?
Me: LIN-07XXXXXXXX
IO: Yes, you do meet NC Memo criteria. And... I do show you have a visa # availble as of March. Our NSC center is working on these approvable cases now. There are thousands of these cases which are similar as yours. We do ask you be patient. You should be able to hear from us BEFORE April 30.
Me: What about March 10 from your "NC Memo Policy Update" released on Feb 28?
IO: Yes, that date was true last week. But we just found out we have more cases need to work than our workload capacity. So April 30 is more accurate and realistic.
Me: Is there any possibility that I still can get approved around March 10?
IO: I wouldn't plan for that.
Me: Are you sure I can get approved by Apr 30?
IO: USCIS will never predict your approval. What I can tell you is you are inline for adjudication.
Me: Thanks a lot for your update.
She seems very positive about Apr 30 date.