I can't give you a definitive bit of law but I would offer the following (UK) orientated view.
A displaced landing threshold is the start of the runway for a landing aircraft.
It is quite conceivable that if the dimensions are suitable that there may be some other quite legitimate activity going on in the undershoot that the pilot would not be told about - even if the threshold was originally displaced because of an obstacle.
Although I would have expected ICAO to treat the situation in the same way the only reference that I can find in Annex 6 Part 1 is about precision approaches and says "An operator shall establish operational procedures designed to ensure that an aeroplane being used to conduct precision approaches crosses the threshold by a safe margin, with the aeroplane in the landing configuration and attitude."