I think this pretty much qualifies as "first-rev": it's a major redesign and the first 11" Air. Also I'm not really talking about 'generations' in the sense of the MacBook{,Air,Pro}X,Y identifiers you can see in the HW info; more like the main board rev which isn't particularly public unless you take it apart. Apple presumably silently rolls out new board revs as they discover and fix problems.
it's actually the 3rd generation Air
By generation he means in this design revision - this air is drastically different to the last one. I owned the first Unibody Macbook Pro, ordered it an hour after release... I'm on my third motherboard. Sometimes the first batch of hardware has issues fixed later on.