JR my recent international experience is limited to 2 hours beyond the shores of the Australian mainland and I don't recall being hit with an in excess of traffic holding advisory and I don't even recall a statutory traffic holding advisory. I did once get caught with an unexpected 60 minutes holding going into Singapore on the day QF32 had its event but it was still a defined time limit. I routinely carried 60 minutes going into Singapore anyway so no problems. I'm not sure what happens in the bigger world of aviation so I don't know whether the term "in excess of" is international phraseology.
To quote the rest of the AIC:
"Notwithstanding any advisories issued, the pilot in command of an aircraft arriving at a destination without sufficient fuel for actual traffic holding will not be accorded a priority approach unless the pilot declares an emergency"
Notice once again the use of the word actual. Airservices, in providing an open ended estimate of traffic holding is basically saying go away or declare a fuel emergency. The AIC is basically saying the information you need is nebulous and we take no responsibility for providing useful information on which to base a reasonable course of action. You do however have the facility to declare a fuel emergency to get you on the ground but that would be your fault. Nothing to do with our system or not allowing ATCOS to use their judgement and experience to provide a better outcome.