EASA and JAR
BillieBob
I understand where your coming from, but!
Shortly after the inception of JAA the CAA aligned the requirements for the maintenance of UK JAA licences to the JARs. The JARs were incorporated into the UK ANO. On formation EASA also adopted the JARS as a starting point. The JARs therefore are now in fact EASA requirements and EU law and must be complied with by UK issued PPL holders.
Any changes that the EASA working parties come up with will have the same effect on current licence holders whether they be JAR or the older UK issue.
I'm in the position of holding a UK licence but hold JAA (as was) Examiner Authorities. I'm aware of the UK Licence holder requirement to obtain a JAR licence to become a JAR Examiner but it is a simple form filling and a fee payment exercise. Current UK PPL-ATPL holders will more than satisfy the requirements that any proposed EASA changes will demand.
At the last GAPAN seminar at RAF Cranwell we were given a thorough briefing by the CAA leadership at the EASA work parties, nothing as you suggest was raised at that meeting. Some EU countries have different standards from JARs such as Switzerland. As I undertstand it a great effort is being made to reconcile those differences recognising and accommodating the reasons for them.
I can remember well prior to the JAA some CAA officers saying at seminars the same as you say you were told but were quickly corrected by colleagues. It would make no sense at all and would cause a storm if it was attempted to require current ICAO UK PPLs to resit exams and Skill Tests. There has not been a precedent affecting any industry in the way you describe. Aircraft engineers are already well established into EASA and none that I know of have had to surrender their licences and be re-examined and tested.