I know their answer in one specific case
Having just phoned them, so do I and it is what I expected in the present situation where determining one's legality is pretty difficult.
do what you want, we'll just make sure that whatever you do it doesn't apply to MY country
That's very true but in practice it tends to be only the "old" southern Europe that actually sticks a finger up to Brussels. Northern Europe (UK, Germany, etc, all the the north of there, and to a lesser extent France) implement all the EU crap with relative enthusiasm, as do the younger EU members (e.g. Czech Rep, Slovakia, Slovenia) which brown-nose every EU official they come across in the Brussels corridors. I am Czech personally and while I can see that they have to always be aware which side their bread is buttered and bend with the prevailing wind, it makes me a bit sick. Watching some of the small country MEPs on the EU parliament videos is like watching the sycophants at a Hitler rally.
I would be astonished if there are any states that do not apply the horizontal derogation (i.e. everything) in the 30th March amending regulation.
Do they have to notify EASA?
One problem with this stuff is that I don't think much of Europe has actually
read these regs
Inside each national CAA, there are probably only just 1 or 2 people who can understand them as a whole.
Many pilots I know of have phoned their national CAA, only to be told that nobody there knows what to do or what it means, and sent the pilot off to ask EASA. But that is bizzare because EASA "only" drew up the rules; they are not any kind of legal interpreter of them. Only a court can definitively interpret a law which is on the books.