Though this is applicable today, from 12th March this will be dangerously WRONG according to the wording of the new procedures:
unfortunately, irrespective of what the UK CAA does, DOC 4444's amendment of 2007 affects operations any time you travel outside your UK FIR.
Some countries such as Japan, have had this position in respect to clearances on SIDs/STARs for a decade or more, predating DOC 4444's recent amendment. China has expected operators to comply with STAR restrictions even when not cleared by such, and to some extent so does Korea. Korea implemented this amendment in 2008.
The result appears to be that every time you get a clearance, it is not unreasonable to clarify the intent of the controller. Even in the states, you will either get a 14 CFR part 91.13(a)
Careless or reckless operation or a 91.123
Compliance with ATC clearances and instructions. violation if you proceed on an assumption of the clearance. If you refer to Jeppesen ATC or State differences from ICAO, it does not clarify the situation.
It would be far more boring but safer if the DOC 4444 "standard" was rational from a safety point of view, and was "standard"ised. Change itself does not have to be a negative, but not providing adequate change management and education prior to implementing change may result in adverse reaction and outcomes.