Heavies load the STARS all the time given that there can be variations with a runway change. In fact, the heavier you are the easier it is as the runway choices are reduced [and a runway may need to be "required"; we live in a country where landing into wind takes second place to noise abatement!]
As to when, that varies. If the domestic guys are doing short sectors, they may put one in prior to departure. Long haul or otherwise, sometime in the cruise. When the clearance is given, the crew verify that the clearance in the RTE page matches the requirement. Simple.
As to the datalink A330 quote; you can't ask or link a route to ATC as they get very upset if they think you've loaded anything other than they've told you. Only in Oz [yet again] do they wait until the last minute to tell you what's happening and then feign amazement that anybody would be able to reduce workload at top-of-descent by pre-empting.
G'day
