I disagree, strongly, with your comment "Some will adopt the practice, others won't want the responsibility".
I recall when the matter of NOTAM for fuel availability was raised at a RAPAC some 10 years ago a survey of refuellers was done (I don't know how or who were consulted), what I said above was the result, along with the opinion that pilots should phone before flight to ascertain availability.
So all I am saying is, no NOTAM don't assume fuel is available - phone first.
I suspect CASA will surround the text in AIP with similar outs i.e. "However ..." "Pilots are reminded that ..." etc.
And why wouldn't you check ahead beforehand??