|But are they diligent searchers ...?|
There's plenty of material for endless references of questions to the Court of Justice for preliminary rulings. In particular, by Article 2 a work isn't an orphan work unless the rights holder(s) can't be found even after a diligent search (on which Article 3 elaborates). This Kat suspects that the concept of the diligent search may be difficult to standardise, especially in the non-digital world.
A further post will no doubt follow soon, probably from Eleonora ...
Thank you, Chris Torrero, for spotting it for us