B787-8 ranges are taken exactly as they are presented in the Boeing's doc. The doc also stated that -9 variant data is preliminary (dated March -14). With MTOW the max range of -8 is about 5450nm, and the fuel limited range is ~10000nm.
Edit: And just downloaded the latest update from Dec-15 which has the 787-9 data and it reveals that the preliminary values we have in AWS db for -9 are actually a few hundred miles too much even, so the range will be updated down a bit with this updated info. (edit 2: actually looked the chart a bit wrong, the range stays about the same!)
(Edit3: You are also quoting a line about A330 but talking about A350?)
(Unless there is some new data on this, apart from a single quote from a news site, no changes are required so far.)