Firstly, thanks to jgs43 for the validation explanation, I honestly feel that the majority of NPPL's would not be aware of this , at least for the SSEA rating. As far as I know the microlight world has stayed with the 13month/ 5 hours, with a logbook stamp from an appointed person.( I speak here as a lapsed microlight instructor)
Re Beagle, there are ,as you know two approaches to the NPPL, either to have it granted as your initial licence or to alter your status to a "day/ UK / reduced medical etc", licence and rating. Most of the NPPL holders I know took the NPPL option to simplify their flying, and/or to fly with a lower medical status. To generalise, they will not be part of an organisation such as AOPA, or even a flying club. The last time they read the ANO was a few bits for the air law exam some years ago, and they wouldn't have a clue where to find AIC's, let alone read them. As an examiner I still find licences and ratings out of date , after many years of JAR. The least the CAA could do is to circulate this latest AIC to NPPL holders