Second you

Yes, I believe you guess right. No real NC cases are approved until March 10. Some unconfirmed news states that CIS began sorting out these memo-covered cases through March 10 and will start to adjudicate these cases after March 10. Yes, very few cases with 485 RD in 2003, 2004 got approved and these cases are the real cases stuck in NC for over 3 years.
1. The vast majority cases with early RD (2003 or 2004) that got approved are most likely related to their WOM.
2. The cases with RD 2006 or 2007 which were just approved are irrelevant to the new memo in some degree.