Has Europe read Annex 1 to the Chicago Convention
It is Article 32 (b) of the Convention which is the operative one here, which says that:
Each contracting State reserves the right to refuse to
recognize, for the purpose of flight above its own territory,
certificates of competency and licenses granted to any of its
nationals by another contracting State.
Not wishing to stir things up, but it seems to me that however half baked the proposals are in practice, legally the EASA approach is supported by the Convention, though I am not at all sure that the EU is a "Contracting state".
If I held an FAA IR I think I would be biting the bullet, doing the exams and the 15 hour conversion before that route disappears!!