That's very true Quattro, technically as long as they have the results from their previous JASO MA testing they could simply compare against MA1 & MA2 to see if they qualify for those specifications; why they didn't do that from the get go is the interesting question, perhaps they did retest as they said in the email to have up to date proof/testing that it meets the proper requirements (in case it's validity of JASO specs is ever contested).
Right on once again that it's not on JASO'S official product listing, and I've really began to notice there's a LOT out there that aren't "JASO Approved" the more I've looked around (as you said, pure semantics). Mobil 1 10W40 isn't, their 20W50 doesn't state any JASO stat. because of it's higher phosphorus levels, all the Castrol oils (partial and full syn) say they also meet specs, Valvoline (petroleum/syn), etc. It seems that mostly "Motorcycle Specific" oils are the few that tend to go for the official approval like Spectro, Motul, Motorex, Repsol, etc.
Here's a link for those that are interested from JASO's latest 2011 Implementation Manual on pg. 6 qualifying the differences in dynamic, static, and stop time indexes for MA, MA1, and MA2 approval on page 6.
http://www.jalos.or.jp/onfile/pdf/4T_EV1105.pdf
One point to note is that if all of the 3 testing results don't fall within a particular rating (MA2 being the highest/best rating) it cannot have that rating. For instance, if 2 of the tests confirm MA1, but one of the tests falls within MA specs, it has to be labeled MA, not MA1. Same with MA2, if it does not completely fall within the specs of MA2 in all three tests, then it cannot be labeled MA2.
http://www.oilspecifications.org/articles/JASO_MA_JASO_MB.php
To clarify, dynamic friction represents clutch feel and how power transfers through the clutch, static friction measuring resistance to clutch slippage under high torque conditions, and stop time index measuring how quickly the clutch engages.