OK - so looking at that document, I notice two things.
- The document itself seems to be a treatise on Aircraft-Pilot Coupling, with a focus on Pilot-Induced Oscillation.
- The term "effective aircraft" seems to be used in the "existing in fact; not theoretical; real;" sense, not the "able to accomplish a purpose; functioning effectively;" sense.
The FBW Airbii seem to be no more susceptible to PIO/APC than any other type based on the amount of time they've been around and no discrepancy has shown itself, and the fact that there is no significant positive discrepancy in accidents between FBW Airbii and other types suggests that Airbus's "effective aircraft" design is no more or less flawed than any other modern type.